Ho, welcome to the forum 
Theres some good stuff in here , though its from the angle of 2 person sex, alot of the stuff in there is really about how to get to orgasm so it should still be helpful.
The thread @Ian_Chimp linked has lots of good tips in it all the way through too.
You might have to try different positions til you find a few that work well for you.
Some options to get you started
- on back with knees up (adding a cushion under your bum can also be very nice with this. Especially if your using a dildo or g spot toy)
- on side with one leg up (can try folding the other leg in towards your chest with this too)
- on all fours (can be good with head and shoulders resting on bed too)
- standing bent over a surface
- on knees (put something under them if your on a hand surface. Can also be good on the sofa, facing towards the cushions, so you can use the back as a support to hang onto)
- sitting up with one leg up and the other folded in as if your going to cross it. (Think typical lazing on sofa position)
- laying on your stomach with your hand under you in between your legs (very good for grinding against your hand or a toy)
- on side both legs folded towards stomach (also good for grinding)
- standing, leaning back against wall, legs slightly open
- sitting, one leg hooked over arm of the chair
- on back with knee up and the other folded in but dropped open to the side.
- sitting on a surface or chair with legs wide open. Leaning back on one hand can also help with this (very nice one if your masturbating for someone to watch)