I'm not sure what type of glitches you're experiencing exactly but here's some stuff, maybe it will help.
If you're seeing "flickering" at the joints, first check all three axis settings for any angle off a bit, and that numerically your prims abutt each other and do not overlap. You're seeing your system trying to decide which prim is "in front" and so it's switching back and forth. Ugly and annoying.
Sometimes seams will show allthough numerically everything is aligned, the same width etc.
Depending upon the build you have a few options that may help.
Solid smooth textures tend "blend" better.
Check the repeat frequency between the pieces. If one is 3x5 and the one next to it is 2x5 but they've got a striped texture 1x1 on all faces, you're trying to match 2 and 3! You'll need to set one at a different horizontal (or vertical) repeat per face, AND adjust the shift on the same dimension, so it will "start" at the same point.
Sometimes putting a solid color, present in the main faces' texture on the mated sides will help, although I'll usually put "totallyclear" there. That can be a little weird at times too, just so you know.
Sometimes, try as I might, I end up with a "perferated" seam that won't go away.
If someone has a fix for that (other than cheating and putting another prim OVER the seam), I'd sure love to know!
Hope this helps!
Btw, if you haven't already, I'd go over to the Ivory Tower Library of Primitives and check out the lessons there. It's modular, so you can pick up where your skill level is and come back, etc. Love that place! (thx to Lumiere Noir!)
