i brush their belly and legs in my lap, with them on their backs. when you have a puppy, its good to practice putting them on their back on your lap and rub their belly, so its a pleasurable experience (and not always for the "dreaded" grooming). also, it helps if you don't expect to do an entire grooming/brushing in a single session with young pups. a little brushing and treats and praise and playtime afterwards throughout the day. you may need to treat if they walk up and touch or sniff the brush and build up from there.