What to Look (and Listen) For
In each room, look around and take stock of what needs fixing or improving. Focus on small, quick-hit changes, not major redos. Here are some likely suspects:
1.  Sagging towel rack or wobbly toilet tissue holder. Unscrew the fixture and look for the culprit. It’s probably a wimpy, push-in type plastic drywall anchor. Pull that out (or just poke it through the wall) and replace it with something more substantial. Toggle bolts are strongest, and threaded types such as E-Z Ancor are easy to install.
2.  Squeaky door hinges. Eliminate squeaks by squirting a puff of powdered graphite ($2.50 for a 3-gram tube) alongside the pin where the hinge turns. If the door sticks, plane off a bit of the wood, then touch up the paint so the surgery isn’t noticeable.
3.  Creaky floor boards. They’ll shush if you fasten them down better. Anti-squeak repair kits, such as Squeeeeek No More ($23), feature specially designed screws that are easy to conceal. A low-cost alternative: Dust a little talcum powder into the seam where floorboards meet — the talcum acts as a lubricant to quiet boards that rub against each other.