We agree with Timberlane Shutters about adding shutters to the smaller window but have you thought about adding a window flow box under the windows? It will add some color and dimension to your curb appeal and it's very simple!

Also you can add some decorative hardware to your garage door. It's an inexpensive trick that many people do to increase the value of their home when they're trying to sell it :)

If possible, I'd construct a matching retaining wall to the left of the walkway. As is, the left side looks neglected and/or unfinished. In addition, a window box with cascading plants would be lovely beneath the small window on the left. Big, black house numbers to the left of the door (possibly vertically) would tie in with the wrought iron porch railings and be easily visible from the street.

a few other suggestions I would make is to add some lighting. A sconce by the front door would be nice as well as along the walkway (low to the ground) or a tall light at the end by the steps. Some house numbers clearly displaying address would be good as well.

I would go to Walmart and buy 3 rhododendrons to plant along the front of the house on the left. You just need color. Some cheap potted florals on the stoop. Done. It's Seattle - someone will buy your house!

I'm guessing you're in the south end of W Seattle. McLendon' and Fred Meyer's should have plant sales coming up soon. They are closer than Walmart, which is in Renton. FM usually has a pretty good selection of pots. Go with a larger size, place it to the left and outside the rail of your entrance. Numbers and a light by the door is really good advice, along with making the windows and door trim larger and consistent .These will draw the eye up towards the door and downplay the garage. You could place a small conifer in the pot with annuals. The tree can then come with you to your new home. W Seattle Nursery is a good source for nice conifers, talk to Bill, their buyer, or Mark and Marcia. All are very knowledgeable. They can also refer a good maintenance person to clean up the gravel and a designer if you need more suggestions. (They used to refer me, but I sold my W Seattle home and moved out of the area and closed my Seattle company. I still stage outdoor areas for homes going on market, but not in your area.) Take a drive around the S. Admiral/Schmitz Park and Genesse areas for more ideas. There are plenty of homes much like yours and these areas are some of the fastest selling due to location.