Run your tongue over her clit. Follow the same direction you use with your finger if possible. If not then just lick up and down. Build up an idea of the shape and size of her clit as you massage it back and forth with your tongue. Stop and stroke it with your finger every so often if you want. Play with the labia as well. Again, licking in and around her vagina will be pleasurable, but unlikely to bring her to orgasm.