How would one train a dog to do something like the Hands Up routine? I've never had a dog, so I'm not sure how I'd get the whole motion across to the dog.
Do this repetitiously until they start getting used to putting their paws up then start working on getting them to sit like that for a few seconds. As a reminder lots of clicks and treats to let them know they are doing what you want. At this point you can start introducing the voice commands.
After they have stay down, you can move into "bang" by once again holding a treat in a way that they fall to the ground, then immediately click and treat again repeatedly. Then you start working on getting them to roll over in the same motion. It's ok to sort of push them with your hands a bit to show them the physical motion you are looking for as long as you click and treat in little increments to show them that what they're doing is "good."
Probably too long winded, but if you look up "bang" dog tricks on YouTube there are a lot of handy guides. My final advice is to pay attention to how much fun you think your dog is having. Some love mental stimulation, others not as much. If the dog is losing interest, then it's probably time to call it quits for the day, as they'll stop thinking the training is fun.
Really, it's quite humorous how close human psychology is to that of my dog.
Once saw a dog that only wanted to perform the tricks in the training ground but not for example at the owners home: the dog had assumed that the combination of (command for the trick && location+training ground) was the trigger. That was fun to see. Other examples included dog trainers that could only successfully give the command while wearing the red coat he was wearing while training the dog, etc.