Once I'm satisfied that the decals are in the right spot, I blot the decal with a damp tissue. I try to use a rocking or rolling motion when I blot the decal.
I've found that the decals are less likely to move if I roll the tissue across them, rather than blotting straight down on them.
Blotting removes excess water and Micro Set, helps the decal to conform to the surface of the mini, and helps push out any trapped air.