Well, If you are using a water slide decal. Poke a few holes in it with a needle, nothing hard enough to dmage the plastic, just to make a tiny hole in the decal, then put down decal softener. AFter that put a dull or gloss coat over it.
It looks nice. The metallics would look better if they were airbrushed, I can see brush marks. This is a Gsys kit, is it not? There beautiful kits. You have some silvering on the back of the head decal EFSF