After 5 boats, I finally learned to lay a decent coat of varnish. I've abandoned the foam brush for a badger. I pay strict attention to the viscosity of the varnish. A half a can of varnish will thicken quite a bit and need thinning for the varnish to lay out flat. (no brush marks) I used to stir in thinner slowly only to find that I would get an uneven gloss.

(Caution-reading this may crash your computer) I now add a few cap fulls of thinner and shake the can vigorously for a several minutes. (I warned you) The next day, the bubbles have disapated and the viscosity is even throughout. I'm convinced that the uneven gloss was because the thinner was not thoroughly mixed.

You almost have to memorize the viscosity of a new can of varnish and try to keep it that way. Now that the weather is getting hot, it starts to set up quick, even in the garage. I like to have it lay out flat in a few minutes. Anything more than that, and I may get into trouble with brush marks remaining.

I now am using finer papers - like 300 grit (once it's level) I learned this from the people at Wind Song Canoes. I get a better final gloss with the smoother final sanding. As far as varnish, I use whatever is on sale. I've tried them all. It's what you do with them that makes the difference. For me, adjusting the viscosity and a thorough mixing of the thinner has made an enormous difference.