Mask off your stock and scratch it up to help with adhesion of the epoxy. Wipe it down with some denatured alcohol. I used some 1/4" fine line tape backed up with some regular green or blue painters tape, whichever I had lying around. I used a hacksaw blade to etch the stock (actually looks pretty good by itself).
I used a tracing of the rim of a 500 ml graduated cylinder for stencil for the radius at the front of the grip area you see in the first picture. Stick a piece of 2" blue tape to a piece of glass or granite counter top, trace the curve from the stencil with sharpie, then cut it with a razor blade. Trim the leftover corners as you see fit to help it lay. Then just peel the curved piece of tape up and connect two points at the tang and trigger guard where you think it would look good. You can do the same kind of thing for the rear of the fore end area, although I just freehanded mine with fine line tape.
Mix your marine tex and spread it on your stock with a tongue depressor or popsicle stick. It goes on about like cake icing. Get a 2" cheap disposable paintbrush from the hardware store and and trim the bristles with a pair of side cutters to about 3/4 in long so it will be stiff enough to move the epoxy around. Brush the epoxy out, wiping the excess off on a paper towel until you have it uniform with no evident thick spots. More epoxy gives a more coarse texture.
Texture/point your epoxy. I used a cutout section of a roller for the re-deck stuff from Lowe's. Using the small piece allowed me to get into the smaller curves of the stock. Just dab it into the material and yank it away, over and over until you get a uniform look.
This is where it gets interesting. It's a lot like doing a knock down ceiling with drywall mud. When the epoxy starts to set, I used a nitrile glove, blown up like a balloon and dipped in alcohol to knock down my peaks. The glove has a lot of give and keeps you from flattening things too much so you can go slow and decide how much you want the texture attenuated. As it gets closer to setting, you can switch to a gloved hand and use a little more pressure if need be. More alcohol means more flattening. Peel the tape and feather in any peaks you create on the edge with the glove/balloon deal.