Rough cut all the plies. Weight them together, then stack them on a 4 mil plastic sheet. Mix, by weight, a quantity of epoxy equal to the glass weight, with maybe a little extra. Now pour the whole mix on the glass cloth, and cover it with another plastic sheet. Use a roller or squeegee to distribute the epoxy through all the plies. When it's all wetted, roll excess epoxy out to the edges of the plastic. Now draw the desired pattern right on the top sheet with a marker, and cut it with a roller knife, right through the plastic.
With the bond surfaces on the airplane prepped, carefully peel one plastic sheet, lay the entire layup into place, then peel the top plastic sheet. Stipple into place with a cut brush. Done.