The girl is on her back with a pillow underneath her butt, you are to the leftside or the right side of her, kissing her neck or sucking on her tits, with a fee handy you finger her vagina, each time you insert making sure the tips of your finger rubs her G-spot. During the inward thrust your fingers put pressure on her G-spot, as you pull your fingers out, you lightly stroke her G spot, repeat this and eventually she will orgasm. this is a great way to change up the pace affter doggystyle/missionary, or to start of your sex session.