Filling the weave with epoxy/microballoons can be done, but it's a lot harder to sand and in the end, may be heavier. After filling the weave and sanding back down, and you have a nice smooth surface, you'll be ready to start adding surface details. For panel lines, I use 1/64" chart tape. I draw out all the panel lines, then lay out the tape. Then I apply a few coats of primer over the tape, feathering out toward the center of the panels. Once dry, pull the tape up and it leaves a chanel in the primer. often, the adhesive stays in the channel and needs to be picked or washed out. I break the tip off a #11 blade and grind a slight hook on the back side, then use it to scrape the adhesive out. Give a light sanding to get rid of any ragged edges and you're ready to burn (flush) or drop (button) rivets. I use a 1/16" brass tube on a soldering iron. I first mark out all the rivets to make sure I have proper placement and spacing, then melt the rivets into the primer. Once done, I again give a light sanding to knock off any rough edges. Now it's ready to paint.

Scott