I know this is common sense, however...
Many people apply vinyl with a soapy water solution. My only advice is, if you do put the vinyl on wet, make sure it is fully dry before applying a clear coat. Give it a couple of days to 'cure' if you can. I've seen bad things happen such as liquid rising to the surface after the clear coat has been applied and it's not pretty.
And, while I'm at it (this is my first post), please don't use Windex or any other glass cleaner to apply vinyl decals. While I thought that this too, was common sense, I've discovered that many of my customers didn't know any better and had been doing it all along. It wasn't until I talked to returning customers that complained of decals falling off that I realized what they were doing. Anything with alcohol in it will gradually eat the glue on the back of the vinyl.
steveclaus
vitalsigns