Landlord's handyman showed me the 2 minute trick with a $3 tube of caulk that saved my security deposit
I was watching him fix a crack in the bathroom tile at my old place in Boise and he said most renters lose their deposit over stuff that takes 10 minutes to fix themselves. Now I keep a tube of white caulk and a $4 putty knife in my junk drawer and I've patched nail holes, tub gaps, and a loose baseboard before every walkthrough since. What's the one cheap fix you always do before moving out?