I wouldn't build shelves or a focus wall -- just a nice picture over the toilet, and reduce stuff on the tank to a couple of items. Pick a rug that coordinates with some color from the art, and maybe the hand towel too. (Holder is ok if you shift its position a bit.) Get rid of the trash can once you start showings, or remove the bag and stash it next to the toilet, at least.

If you're selling I would honestly just paint it (not gray because it looks like it will clash with the warm floors), put in a pretty rug and hand towel and call it a day. No need to do so much with this space.

If this were my powder room/half bath and I was going to put it on the market, I would add two mirrors over the sink like the insp pics below. One mirror on each wall over the sink.

I would also get rid of that ring towel holder and put up a rail towel bar in a good location in the bath. Right now that towel holder is in the wrong spot as can be seen from the current photo posted. Or put a smaller ring holder in a better location.

If you do have the budget to change out the sink for a corner sink with a small vanity (see below), I believe it would be very helpful in both looks and the sale of the house.

Right now, people will see that bath as a problem and not a solution if you don't at least fix it up enough to be pleasant. Don't add a feature wall. Don't put in a lot of money. This can be done for a budget price, especially if you don't elect to have the storage below the sink.

Found a sink with vanity - but don't know your sizes or style. Google can be your friend :)

If you want to cover up the pipes you can put on those white covers for less than $40. I have them in my head as socks, but I know that isn't the right term :) See the link below.

http://www.globalindustrial.com/p/plumbing/drains-traps/sink-drains/2003w-handy-shield-p-trap-supply-covers-white-806159?infoParam.campaignId=T9F&gclid=Cj0KCQiA0vnQBRDmARIsAEL0M1lkmDdiM72ANEkgG9AE7oy7X4Z6IhuB7BQiabyZ3anLuMTht_UGXpgaArHTEALw_wcB

Definitly remove the waste basket from its current location - people will assume you put it there to catch water from a leak. You would be surprised what buyers think. I'm a Realtor and hear their comments all the time. They assume the worst.

I like the way the texture of the beadboard gives a finished look and warms up this little powder room. The sink from Home Depot looks nice too. No pipes showing.

http://classiccasualhome.com/2012/12/tiny-powder-room-before-and-after.html

I think the sink is adorable and isn't the problem. A simple skirt made out of ticking fabric (beige and cream or something neutral) would easily conceal the not-so-attractive mismatched pipes. I agree the faucet isn't great, but it's not terrible either. Unless you find a better one for a decent price (try Craigslist and eBay) that works with your single hole sink, I'd leave it.

For a simple remodel, I would first remove the over-sized, crooked towel ring and possibly replace it with a simple hook, which would be more to scale in a small powder bath than the large ring. At a minimum, find a better spot for the ring or at least straighten it and fold the towel in a way that it doesn't drape on the side of the sink. Then paint the walls with a neutral color. If you're wanting grey, maybe a warm grey like Ben Moore's Classic Grey-- something that looks harmonious with your floor tiles which seem to have both beige and stone/grey in them. I'd leave the simple mirror you have up rather than add a nautical style one. If you can find a light fixture that is more of a classic sconce rather than the modern style fixture, that would help I think. I'd remove the rug for showings at least, along with all of the clutter on surfaces. Good luck!

A large framed colorful poster (under $50) on wall facing the door would be a good addition. Use two matching framed mirrors ($20-$50 each) as Denita shows. A $10 fabric skirt velcro'd onto the existing sink would be enough, and hem-tape it to proper length. https://www.amazon.com/Carnation-Home-Fashions-56-Inch-32-Inch/dp/B007VMC3NC Sure, buyers will look under it, but they'll just see mismatched pipe colors. Buy a $10 covered waste paper can. Check the light bulbs to see if they are bright enough or if they have gotten dimmer and grayer.

No gray paint. Here's a striking, colorful artwork that gets attention.

I think a simple pipe cover is plenty under the sink. Paint everything a creamy off-white, add a hand towel with a nice bright print. And a cute light fixture. Space is too tight for bringing in a bunch of stuff.

I would just paint and call it a day if you are trying to sell, it will be cheaper and less time consuming. The new owners can add what ever touches they want :)