Determine the cone rating for your pottery. Kiln temperatures and the time the pottery will be fired combine to give you a cone reading. "Low-fire" is cone 4 and below, "mid-range" is cone 5-8 and "high-fire" is cone 9 and above.
Determine the proper flux for your cone rating. Lead and boron fluxes are used for low-fire glazes. Sodium is one of the most popular fluxes, and is used in most mid-range glazes. High-fire glazes can use a number of fluxes, including potassium, calcium, magnesium and barium carbonate. Each flux can give a different finish and has different properties, so experimentation with different fluxes in overglazing can help you determine your preferred fluxes.
Mix even parts of the silica, flux and sticker in the bowl. Combine using the brush. If necessary, add water a little at a time until a brushable glaze is achieved.