I would hang it from one of the cabinet doors - search for "over the cabinet towel bar" for lots of options. I have the Umbra Schnook in my small 3-piece bathroom.

Thank you--I hadn't thought of the door! Not sure we have clearance for an over-door towel bar though since the tolerance of the door to the frame is pretty tight. Will check.

No go for over-the-door bars sadly. Too tight so it rubs (at least for the one we happen to have on hand).

between the window and the medicine cabinet with a round holder

Just wondering why you need a hand towel holder with the towel bar right next to the sink? If you want a towel, can you just fold it over the bath towel?

Is that room door usually closed during a shower? Is that the shower to the left of the pony wall? If so, you could mount double towel bars on the door for the bath towels, and use the existing bar on the wall for hand towels.

Or, mount a bar or ring on the window apron.

I think Toronto meant and over-the-door rack on the vanity cabinet.

I like towel hooks & my vote is a hook on wall on right side of mirror above the tile backsplash you’re planning. I’d think about changing out towel bar on left to hooks also. That’s a tight space for the towel bar for bath towels. Is that the shower across from vanity in lower left side of pic? If hooks were used is there a spot closer to shower towels could be hung?

Thanks all! @barncatz that's a good point--I should have included that option in the poll. We definitely could just use (and in fact for the last year, have been using) the bath towels and that is my partner's preference for simplicity. (This is a master bath so it's rarely used by guests, though is somewhat regularly used by kids for hand washing, so that's why I'd prefer to have a hand towel.)

The door is closed during showers and yes, that's the shower just out of frame to the left, but we have a door-mounted towel bar in our other bath and don't love it for bath towels. The door is also open into the bedroom most of the day because we get a lot of light through that window, so that puts the towels into the bedroom space, which I don't love. (Right now you can see them, but just barely.) We could test out a hand towel over the bath towel and see if that gets used/put back consistently, though.

In the first photo on the counter are the robe hook and towel ring that we already own, so I'd ideally like to use one of those, though if I find a towel ring that matches the black ceramic towel and toilet paper fixtures, that would be great too.

(And yes, it was an over-the-door rack on the vanity door that I tried that unfortunately doesn't fit. I can see if there is one with a skinnier over-the-door piece, but because the cabinets are flush inset, there isn't much room between the cabinet door and the frame.)

@KW PNW Z8 we had actually originally planned for hooks right next to the shower (that's why we have that robe hook) but with some mid-project design changes, we ended up not having enough room where they were planned. Tested out both options where the rod is now and decided we liked the rod better overall. A pro to the hook if we put the hand towel under the right sconce is that it won't hang as low, though--I think that's part of why the towel ring looks off there. My brain wants it to balance the outlet on the other side, but it doesn't.

I would place a towel ring to the right of your mirror; most people are right handed; functionally I think it is the best area. I have hand towel rings in all my bathrooms.

artemis, thanks for extra detail on options. My vote for hand towel is now still a hook - not a ring - on wall to right of mirrored cabinet & positioned so the towel hangs just a little bit over the tile that’s planned. I think that height will be an easy & natural reach but will also leave the back side of vanity counter clear for setting items in the spot under towel & not be in the way of towel. So, a cleaner vanity top look. I wouldn’t worry about balancing height with light switch or towel bar on left side at all.

ETA: just seeing kculbers post on towel ring. Confused as her towel ring is on left but she says prefers right. But, look at vanity top on right - if that ring & towel were on that side, the towel would be draped over the standing mirror unless ring was moved more to right. Towel hooks look ok being hung higher than a towel ring can be hung - IMO

I voted for a ring on the right. Personally I don’t care for hooks - some don’t grab towels quickly and the towel ends up on the floor.

I had the same issue and I don't mind using the towel on my shower door.

I like hooks outside of a shower. You can hang the towels off that and then put the hand towels in that spot.

You want to avoid drips from wet hands going farther than the counter.

How many hand towels will you have?

You could do this:

Bath towels behind, hand in front? We used this in our last, small, primary bath, and had two of them in the hall bath, one above the other, for the kids’ bath towels and any overnighters’.

Just the one. We actually do have a towel rack just like that one in our primary bath (though it's rarely used!) and tried it out in this space, though I didn't have the hand towel in mind at the time. Will try it again to see. Thinking I also need to get the backsplash up and then try the towel ring under the sconce to see if it works better for me once that piece is in place, and then make a final call.

We mounted an open rail towel holder to the side of the vanity. We had no other spot for it.

KP BNW 28: even though I think a hand towel ring should be on the right (more functional since most people are right handed). Mine is on the left, as I like to keep my large hand mirror on the right of my vanity. A towel ring on the right would not work there.

Be sure bath and hand towels match and place a hook for the second towel behind the door (rack won’t be as crowded and will also dry better).

Beautiful bathroom! I’d just use the towel rail you already have, or one like bpath suggested. With the photoshop of the (additional) towel ring on the right, all I see are towels and not your beautiful medicine cabinet, vanity or countertop.