One way we start at work is we started with a phone book duct taped shut. You can either free shape it by standing in front of it with treats and waiting for any interest and to click and reward for. Then build the criteria to only clicking for paws. The other option is putting that phonebook between your feet while you sit at a chair. Most dogs will either crowd in or even jump on your jump. When then jump their front feet up you just stand and let them fall, as soon those paws hit the phone book click and reward. When that is secure you'll ditch the chair and back up.
There are other luring ways such as pointing until they "bother" the spot with their paws and you click and reward.
Back feet are best done, imo, free shaped OR by using pressure by walking into the dog until they take a step back and you click and reward. The problem with the second method is a lot of dogs become hyper reliant on the pressure.