I always apply decals over a gloss surface and using Micro SET-SOL products. Finemolds decal sheet for TIE fighter is excellent quallity, I mean decal film is really good. I did not have any problem with them. I did not cut film excess in mine. If you have interest to know how they worked, I posted some pics of my finished model some days ago in this forum, please take a look.
http://www.finescale.com/fsm/community/forum/topic.asp?TOPIC_ID=17836
Enjoy modeling!
Lu