I'm sure I'm not alone in my inability to install trim without gaps. Recently I redid the trim in the mbdrm. I decided Enough is Enough, I'm Doing This Right! (and by "right" I mean "so it looks good" without utilizing enough caulking on gaps to waterproof the hole in theTitanic and refloat her, without investing 20 years in becoming an expert finish carpenter)

Enter the Family Handyman website. Lots of straightforward pics. My problem has always been tilting inside corners on baseboard. Yeah, I know you're s'posed to cope, not mitre. I suck at coping so I mitre...and the bottom of my baseboard gaps at the joint.

Family Handy gives a trick that involves placing a screw in the wall near the corner, then adjusting it in or out to remove the gap in the joint. He describes it with a coped joint but it works just as well with a mitred joint...

just be sure both ends are mitre true, not always easy when cuting the end of a long piece that wobbles on the saw! A trick I found to eliminate THIS problem (can't remember where) is to cut your corner pieces first in short sections so they're managable, then bevel longer pieces onto them

P.S. If the attached Link doesn't work for you, Forboystoo has very kindly attached another below!

Here is a link that might be useful: Family Handyman Install Baseboard on Crooked Walls

This post was edited by Baroo2u on Sat, Oct 26, 13 at 14:27