How do you deal with TAMIYA decals?

I don’t–most are thicker than a 2X4…

Couldn’t agree more. I’ve built several Tamiya aircraft kits and have never had a problem with their decals.

Surprisingly enough, I 've never had too much problems with Tamiya decals. They’re rather on the thick side but I find them easy to apply. One thing though, I do not apply decal softener when the surface does not have too much raised lines or rivets. I find that it works better without the softener. But you are right they wrinkle specially if the decal surface is a little to big, like letters in the fuselage of your Spitfire. You should try the Dragon decals, man they are hard! You can lift them off their backing and it stands up. I also mix a very little amount of Elmer’s glue with the water I will use.