builds, paints, and decals 
When everything is to my liking, I apply Micro Sol. This helps the decal better conform to the minis' detailed surfaces. It may take a couple of applications of Micro Sol to get the decals to set the way you want them to.
Sometimes, I'll have a decal that needs to be trimmed after it's been applied. As an example, I'll use the I-94 Enterprises' invasion stripes. I cut the decals a little longer than I needed. I wanted to make sure they were not too short for the wings of the True North Typhoon mini.
If the decal is on an edge, I'll run a very fine abrasive stick or sheet gently across the edge. If the decal is in the middle of a surface, I'll gently "rock" a curved hobby knife blade across the decal.
Once the cut is made, I'll soak the area with Micro Set, and then use a brush to gently remove the unwanted portion of the decal.