RE: Now I remember why I hated those stickers you had to put in water....
If they are water slide decals, then a little preparation goes a long way. Clean the surface that you are going to install the decal and be sure it's clear of all impurities, oil, dirt, etc.
Determine if the decal needs a top carrier coat. If it isn't shiny on top, it probably needs some clear decal film brushed over the top of it. I use clear decal film from Squadron available mail order. Brush it over decal and let dry.
Then get a nice sized shallow bowl of hot water and let it cool a bit, insert decal and let it get ready to float, 1 to 1 1/2 minutes is usually plenty. Pick out the decal on the paper and position it above the place you want it, touch it with one finger and slide the paper out from under it with the other hands fingers. Be gentle, careful, patient, and don't drink or fight with the wife before attempting.
A guy named Sean Magreeney on 049 Collectors makes vinyl decals for a lot of different models, I have some of his and they work great.