I didn't start masturbating until I had already started having sex, and just wasn't getting it often enough. I couldn't believe I had been missing out for so long.
What works for me is using a decent sized vibrating dildo(on low to medium). Then I use a clit teaser on the side (directly on the clit doesn't work so well for me). I put a pillow under my knees. This positions the dildo just a little more firmly on my G-spot and keeps it from coming out when I get so wet and the contractions of my vagina would push it out. This also gives me a free hand to play with my breasts which always makes me hot. I move my hips in a circular motion and the clit teaser in up and down the side of my clit. I can keep going for hours with the combination.