Root cause! 

Yeah, leave more time for paint or cement to cure or set.

Use less-instead of one coat of paint, which you might tend to apply heavily, apply several thin coats and build up color gradually

As for gluing, use less.  It doesn't take a lot for the bond.  As Laurie noted, you can tack pieces in specific spots to hold the pieces, then go back and apply a little more along the join.

But yes-patience, patience, patience.

I usually have a couple of projects going at once, too, so while I wait for something to dry, cure, set, on one project, I can turn to another and work on it, in the meantime.   I paint figures, and I do the same thing with those, too-I'll have several going at once.

Hope that helps!  And do show us what you're working on!

Best regards,

Brad