Make signs like "gather" "family" "welcome". Do seasonal stencils or paintings on them. Add silk decor.
Unfortunately, many Habitat for Humanity Restores no longer accept them as donations. Check first before you make the drive.
Here's what some other Hometalkers have done:
If the doors fit your cabinets, and you've removed them for some reason, keep them somewhere safe. You might want to put them back someday.