Make It Look Better
Chances are, if you buy more expensive stuff than you had before, it will look better once stuck in place. Like if you have cheesy confetti floor tiles, try marble. Just ignore the mocking laughs of small children in hats when they learn that you cut another tile in the wrong place and you have to make an 11:00 run to the Depot.
These Things Are Your Friends
Things that cover up mistakes are your friends. These things include: crown molding, caulk, mortar, 2x4s, duct tape. Duct tape can be used for most anything.