I think you need larger art. Look for a headboard or something unique to turn into a headboard. Consider flipping the bed to the opposite wall, this would cover some to most of your bad planks and allow you to be more flexible with the rug and give a bit more privacy when sleeping. Put the chair into the corner with the window with the table next to it. Put the bookshelf between the two doors. Look for bedding and curtains with red, green, and/or beige to go with the rug. Hang one curtain rod next to the ceiling and from wall to wall, so when you open the curtains/drapes they'll be outside the window frame allowing more sunlight into the room. Agree with you about fewer things in a guest room. This allows you to personalize when you have guest, have a book out by their favorite writer, personal pictures with them in the photograph.....

I like how considerate you've been about your guests' needs. The room will feel a lot more complete with a headboard and bed skirt. You can use interesting things to create a headboard (e.g. an old door or shutters, a wall hanging). A bed skirt will help finish the bed, but you may still need a larger size quilt. Something that uses one or more colors from the rug would help tie everything together.

I'd hang new curtains from the ceiling to the floor. Your paint color looks light but can't tell quiet what color it is. If your rug has to stay I'd pull your color scheme with it in mind for the curtains and bedding. Luxurious bedding for me is a fluffy duvet I can burry into with lots of pillows! I agree with your minimalism and also the large art piece or focal point suggestion to "fill up" the space without adding "stuff".

Sheen too much? Less is more - re-use pillows somewhere? Right color?

A stool, and maybe one bit larger for luggage? You didn't ask about this, but just to see a fan.

If you have quite red [with brown?] bedding maybe your curtains are ok.

But if you have ivory bedding, maybe one red gingham in: shams? or curtains [short, if sun doesn't stream in]? bedskirt not as much imo -with rug right there...

If possible try placing the bed in between the windows. And side tables under your windows.. With lamps on each. The black white lamp is beautiful. Get another similar lamp, I mean size of current lamp is too small. Even if you can't find the same lamp but at least find something of similar size and style..
Lamps and a small flower arrangement is all you need on both side tables.. Keep a small fancy plate etc for guests to place their watch Jewellery on before sleeping. It won't be a clutter.. You can use runner kind of placemats to further brighten your side tables.... Without really adding too many things..
The quilt is good. Just treat it like A throw. Get geometric or floral sheets and plain duvet. Pick colours from the quilt only..
Place your book shelf to the wall between the two doors.. And the dresser and mirror to the wall opposite it currently..

If possible hang the mirror a little nearer to the dresser.. It's a little higher right now..
Add a bright colour cushion to arm chair.. And hang three large rectangular paints on the empty walls.. Just make your own abstract stuff using colours from the rug or quilt..

Great ideas. Interesting thought about bed placement between the two windows. I had always thought of placing the bed where it is right now because it allows you to sit on the bed or lay on the bed and look out the window. There are lots of trees and historic row houses across the street. I love looking at them but don't know how important that is to other people. I don't think I would like to put the head of the bed where the table and mirror are currently located because the bathroom door is right there - next to where the arm chair is currently located. I don't know why it seems unappealing to me to have the head of the bed so close to the john. I suppose that is a common arrangement?

I just dove onto craigslist to look for antique headboards. One listing is two blocks away! We shall see. My thought based on the suggestions above is to get a headboard and foot board in place first. Then depending on the style and color determine whether a bed skirt is needed and what linens to purchase.

Walls are Benjamin Moore Halo.

I agree, leave the bed where it is for the view. I recently moved my bed from between two windows and I had no idea what I was missing. Much nicer to look out a window than towards a wall.

Curtains are all wrong. hung too close the the glass, the rings should be much higher up and the length of drapes should touch the floor so it feels luxurious, regardless of window size, especially for a bedroom.

the tones of the room are very old fashioned and drag it. But if you don;t want to change the rug, that is hard to uplift. You need some vases with flowers (real or faux), the bookshelf to me seems out of place in a guest room and makes it look like it is a room with unwanted furniture or things.

Any thoughts as to whether I should paint this book case? I am usually quite opposed to painting wood but this is some kind of Amish veneer piece that is practical but certainly not precious. If so, what color? I think the current color is pretty off.

I don't love this particular bookcase itself, but I do love having books in a guest room when I stay in other people's homes. I enjoy seeing what they read and finding new books to read while I am visiting them. Books to me are a real treasure. I looked into having built in bookshelves made for this room but decided I didn't want to spend the money.

The bedding I posted was going for transitional, and bit of pattern. The texture of sham, a few flowers. I see the historical photo is it? and so those things are certainly you, and a part of your home! I also like idea of solid ivory bedding with your quilt folded at bottom, but I think you might use it on the chair, or as you said in another room. Color should strengthen presence of red in rug.

Yes I'd paint the case but bedding first!? Table is barn red??

I think I am going to use the following two photos as a bit of inspiration. The general color scheme from the one with the grey walls and white trim. I like the mellow color of the linens and wood furniture. I will see if I can somehow make this mesh with the rug that is there. (It was my grandmother's, and a really fine, wool, braided rug, an antique). If it doesn't look right then I will find a replacement rug.

The other photo I like for the window treatments. I think I am going to go with an interior mount roman shade. You cannot see it in the photos but the window trim almost meets the ceiling in a sort of awkward way, and there is no wall space to the right of the right window - it goes immediately into the corner of the room. Because of this, I think that hanging curtains are going to look odd as I cannot stack them evenly on either side of the window. I like a simple roman with ribbon outline. I like the idea of the shade being the same color as the walls - a light grey, and the ribbon accent being another color. The white shades in this picture are very pretty, but impractical. I don't want to police my guests to make sure their hands are clean when they raise and lower my white shades!

Have you thought about insulating window treatments? Ours happen to be made in the USA and they have pretty quick payback periods. Aside from that, more neutral colors would help open the room and make it look larger!

Roman shades are a great idea with your window arrangement. The rug in your first inspiration pic works because all the colors in the room are muted. Right now, your room is mostly muted colors too - except for the rug. You can take it out and you'll have an easier time with the color scheme, but I appreciate trying to make personal items work even if the end result isn't "perfect."

If you do neutral bedding, then to make the rug go with the room you would need to add bright colors in a few other locations. I think it's easier to mix bright greens and muted greens than bright reds and muted reds, but you could do either. I'd add a green pillow on the bed, the ribbon on the roman shade, and the fabric on the armchair (or at least the pillow). Then there's one repeated element that ties back to the rug specifically.

just a photo with brown and red and green:

ER612 - My goodness, I don't know how I missed the picture you posted last week. Thank you so much. It is incredibly helpful to be able to visualize the bedding. I like the idea of a kind of linen, oatmeal color. And I like the idea of having varying shades of oatmeal, ivory, mushroom for the bedding and romans. I think having a few different shades and textures of the same family of colors will be nice.

I am thinking of this as a bedskirt:

http://www.bedbathandbeyond.com/store/product/b-smith-linen-hemstitch-bed-skirt/122595?categoryId=12020

The picture above the bed is my great grand father's WW1 regimen. It is always fun to find his picture among the many faces. I hung it so high up because the frame is very fragile I want to make sure people can sit up in bed without hitting their heads on it. We have a lot of tall visitors. I am also pretty tall, as is my dad 6'1, and we hung the black mirror together, so I am not surprised that it is on the higher side.

The table is cherry wood. I will not be painting it. It currently has a table pad on top of it to protect the surface. It is nearly the same color as the wood. I am debating putting a table runner on it to lighten it up. I am not a big fan of cloths on dressers and side tables though. I think they are a bit fussy looking and collect a lot of dust so I am still in limbo on that one.

Wait with adding a runner. I think the curtains alone will make a huge difference in brightening the room. Here's the bedding from my pic: Grand-Luxe-Payton-3-piece-Duvet-Cover-Set

What color were you thinking for the bedskirt? I like the white bedskirt with white sheets.

Made in USA sheet set <$50: Grand-Luxe-Main-Street-Dobby-Stripe-310-Thread-Count-Egyptian-Cotton-Sateen-Deep-Pocket-Sheet-Set

How fabulous to have a photo of your great grandfather's unit!

headboard, crown moulding, hang curtains higher, wider, and to the floor, new bedding but put the quilt presently there on a quilt stand, add art and hypoallergenic plants.