The potty tips everyone else gave you were good but I wanted to give you my own experience with taping the ears. Yes, shave the tips and if you want, tape them but some people say to make a ear shaped stint to get them to stand...the problem with that is 1) it's REALLY hard to get a wiggly little puppy to be still long enough to put in a stint and 2) you can cut off the circulation to their ears. We used thick gauze folded in half when we taped Tucket's ears and we only had to do it for half a day when his started popping up on their own a few weeks later. They can come up on their own but it doesn't hurt to give them a little help
Yorkies are adorable either way but I personally think that they are a lot more expressive with their ears up. Congrats on the new puppy. Your babies are beautiful!