I agree with all the responses but I would also include some type of anal stimulation. A women has so many “feel good” spots in and around the anus. It sounds gross to those who have never tried it but once you expierence the wonderful feeling you will love to include it during your masturbation sessions.
In summary, my advise to you is to take a warm shower or sit in a warm tub with some type of bath oil so you can completely relax. As you bathe, tease yourself by massaging your breasts, nipples, clit, etc.. After bathing retire to your bed or reclining chair. Use plenty of lube on you clit and vagina area. Using your finger, without the nails, stimulate your clit by rubbing It in circles, left to right, and up and down. Even taping it works good. While your doing this insert some type of stimulation device into your vagina and also your anus. Stay relaxed and I guarantee you will have a great orgasm. Maybe listen to your favorite music also. The key, in my opinion, is to stay completely relaxed. Remember, the biggest sex organ we have is the brain!