If there are no pawns the enemy bishops are strong as well. Try to restrict the mobility of the enemy bishops by closing up their diagonals. If you can not post your knights so they are hostile to the enemy then try to trade them off for the opponents bishops. A knight is a short range piece, it requires protection to keep from being chased away by the enemy king. Pawn and knight work to complement each other.
Knights are like pack mules that are used on mountain trails.
They are slow ground animals. While bishops are like airplanes that need to fly unencumbered by mountains which only get in their way. If you understand these fine points you will be developing your pieces toward the center and then be asking yourself whether you want to fight an air game or a ground game. Enemy bishops should be restricted by closing their diagonals or traded off with your unhostile knights. If it has helped improve your game I would like to here about it.