The basic is your hands on her hips/thighs. You could hold her hands = that gives her somewhere to put her hands which is always a problem for us. You could run your hands up and down her sides. Sexiest thing a guys done while basic grinding? Nibble on the back of her neck.
I like it when the guys hands wander where they want. If I feel uncomfortable then I'll move them but it all depends on the girl. Girls have different definitions of what groping is so just go till she let's you know to stop.
Just rub her sides and don't think too much about it. Be natural. If she doesn't like it, she'll let you know, hopefully nicely.
well I would grab the guys hands and lead them myself so If the girl does that then its kinda easy, if not just put your hands on her hip/thighs