well i dont know if my method is best at all, but my gf loves it
i think position helps, she lies down facing up, i lie slightly next to her facing down, this way we can still kiss while i finger her reach down and use my middle finger, this works well as my palm is flat and pushes against her vagina as i do the fingering, start slow and build up a bit of speed, after a while i switch to my thumb as you canuse it more quickly and faster util she cums. dont know if it will work for you, but she loves it
