Buddy nailed it with the surface prep being the most crucial step in ANY painting job. This includes what you do around the house as well. As for flies, I buy cheap nail polish from the Dollar Store and follow them up with a coat of clear coat like Sally Hansen's Hard As Nails or any clear coat nail polish. This really increases the durability of the finish, and is compatible with the other finger nail polish as well. You want to stay away from dissimilar coatings like enamel base coat with lacquer clear coat, as you may experience a "wrinkle finish" from the solvents in the dissimilar coatings.
Have fun, and as Buddy said, if you do batch jobs of painting eyes followed with a clear finish, then your tying won't be interrupted waiting for coatings to dry. The eyes will be ready when you are.
Joe
Joe Valencic
Life Member FFF
Rod Builder in Chains