Lesbian strap-on sex instructions.

Find the right dildo. Here are some tips for buying the right dildo for your needs.
Get used to your new toy. Put on your harness and dildo and get used to how it feels before jumping right into bed with your partner. Have her help you into the harness. The tighter it is, the more control you will have and the more sensation you will feel.
Don't forget foreplay. Kiss her. Touch her. Get her excited and turned on before you penetrate.
Put a condom on your dildo and use plenty of lube, even if she seems lubricated. Slippery and wet is much more enjoyable.
Go slow and easy the first time. Angle your dildo upwards, not back toward her spine. Let your partner guide you in how fast, slow, deep, rough or easy you go.
Try different positions. Old fashioned missionary position allows for face to face intimacy. Doggy-style allows you to penetrate further inside her.
Use your hands. Remember the foreplay? Keep at it, caressing her where she likes it most.
Mix it up. Experiment with oral sex. Watching their lover go down on a dildo is a big turn on for many dykes. If you want to experiment with anal penetration, take it slow and easy and use lots of lube. Remember to change condoms any time you change orifices.
Communication is key. As with any sex, talking about what you like, don't like, what you want, what feels good is very important. Listen and pay attention to her body language. Ask her if it feels good. Does she want it deeper, faster, slower?
Remember if you share any sex toy, to change the condom!