Here is a simple description in this link
http://www.modelgasboats.com/Resourc...and_Finishing/
I have never uesd anything other than West Marine Systems Epoxy even in filling grooves. As it says in the link, you can work it into the grooves with a putty knife, putting pressure downward. If this is your first seal, you will be surprised at how forgiving the epoxy is. Being self leveling, try not to worry to much about the process. I don't think I would drag the paper towels across the surface after it has had time to cure.
The plaing cards are great at removing excess (Squeegy). Being that playing cards are laminated, they allow the epoxy to whick. I would be concsious about the edges, trying to keep excess to a minimum while ensuring coverage. There are a lot of ways to skin a cat, but this has worked best for me.