My favourite gag to use is the penis gag, and I mean the actual gag not my bodily equipment. It gives the girl something more to think about and provides a little discomfort at first, but she soon gets used to it and I have had requests to use it over others.
A bit gag for aethetic reasons, looks so very lovely and boy doesn't it let out the drool.
A Jennings gag for when you want to use the mouth, or play with the tongue. This also seems to be quite a humiliating gag, but I don't really know why. It wasn't explained to me, can a sub who finds these gags humiliating explain why?
But for keeping a girl quiet the absolute best is to stuff the mouth with rag, panties can do quite well if your girl wears them but usually you want a bit more material to get the cheeks bulging a bit, and then cover the mouth with tape. Black electrical tape is excellent and looks nice and is quite easy on the lips and skin. Alternatively you could use a leather strap to keep the material in but this is a little harsh and tends to push the material further in when all you really want is to keep it from coming out. The loudest screams are nothing but a muffled squeal with this gag. Perfect for harder sessions when the neighbours are so close
Jason