A great way to deal with really icky seams.

I saw a version of this tip in an issue of FSM, and thought I'd try it out to get rid of some really bad seams on a kit of mine. It pretty much goes as follows:

-Superglue the two things (like fuselage halves) together. Don't worry about being frugal with the superglue.

-Working very quickly, put a bead of superglue on top of the seam.

-Run your finger along the seam (through the superglue), spreading the superglue along it, and removing the excess. (Don't worry about the glue on your finger. Don't touch ANYTHING until it dries. When it does, it'll come off on its own eventually.)

-Immediately, while the glue is still wet, start dry sanding with a coarse sanding stick. The plastic dust will get lodged in the still-wet superglue, and fill any seam almost instantly.

-Finish up with smoother grades of sandpaper to get desired finish.

As I said, I just used it on an ill-fitting kit of mine, and it works great. Wereas once it took me 20 minutes to get a decent seam to disappear, this method allowed me to get the same results in about 3.

Hope it helps!