Most girls lie on their back. But you can also masturbate lying on your stomach or your side or sitting or standing. Discover what you like best.
Some like to have their legs wide apart, while others need them very close together to increase the pressure in the pelvic area.
Instead of stimulating your clitoris with your fingers you can also try a vibrator or do it in the shower or bathtub, using the water to stimulate your clitoris.
Some girls don’t caress the clitoris, but rub their vulva against something, like the mattress or a pillow or old teddy bear clasped between their legs.
Some girls like to use their fingers of one hand to stimulate their clitoris, while thrusting one or two fingers of the other hand in their vagina. You can also use a dildo to thrust. The combination of clitoral and vaginal stimulation can add to the excitement.
Some get excited by stimulating their G-spot. There are dildo’s with a curve, especially made for this purpose.