What have you done around your place that has made it more liveable/likeable for you? Bonus points if you had to build it!
I made an automatic door closer for a cavity slider. The cat was very good at opening the door, but crap at closing it, making for nasty draughts in winter. With some sash cord, a small pulley and some electrical conduit I built an unobtrusive, hook-on door closer. Now the dog (who replaced the cat many years ago), and children can open and get through the door, and it closes right after them. I've still never seen its like available commercially.