1. Studio Lighting.
Close the blinds and make your room dark, find
some lamps laying around the house, or if you don't have any, buy a cheap lighting kit. You need the lighting to be good for the video or else it will be dark and hard for people to watch.
2. Tape down the lego boards that you're going to use in the film, so they don't move around while taking pictures.
3. Use a tripod.
You can buy a tripod, use the one you have, or make one out of lego. If you don't use one your camera or smartphone will move around a lot while filming.
4. get a camera remote.
If your headphones have a little volume button on them some where, you can plug it into the smartphone or tablet that your using, so when you press the button it will take a picture with out you having to click the screen on phone or table. This will help you to not accidentally move your camera around when you're trying to film a stop motion video. You can also buy a camera remote for under $5 On eBay or amazon.
5. Download Stop Motion Studio app If You're using a phone or tablet.
stop motion studio has so many different editing tools for only $5, Plus the built in app tools make stop motion films look more professional and are easy to use.
It's on both android and iOS.
Learn more about stop motion studio https://www.cateater.com/