Some people start with a "skim coat" of resin (a brushed layer of epoxy) which gives a better external surface, but also is a little heavier then a simple layup. Sometimes I spray paint in my mold. The purpose of either a skim coat, or painting is to reduce the the porosity, or pin holes that have to be filled in the finishing process. It is also a standard procedure to mix resin with filler like cabosil, ( not sure if that is the correct spelling?) One general term is to call it "mud" which is then spread into sharp corners where the cloth won't lay. Nose rings, tail posts, wing fillets, and even sharp leading, and trailing edges. Sometimes a bag, like a cake decorating bag is used to pump the mud into the sharp areas. I make my bags out of poly, or nylon film. A totally different approach to getting your cloth to lay in the mold is to use two layers of say 2 oz. cloth in the mold instead of one layer of 4 oz. I don't know what kind of cloth you are using, but some cloths lay down better then others.
Cloths referred to as "crow's foot weave" and unidirectional are good choices for our models. I get a cloth from thayercraft.com that is 3.7 oz unidirectional, which I recommend highly.