Tape down your baseplates: houses & background structures can become unintentionally animated with the slightest bump. Use tape.
Camera lockdown: Avoid jittery videos. Just like taping down your baseplate, you'll want your camera taped down or on a tripod.
Camera movement: sometimes you do want to move your camera to create a cinematic effect. Hollywood films spend big money to do the same.
Reflections: LEGO bricks reflect light and can have mirror-like properties. Learn how to minimize unintended reflections.
Control your own shadow: lights should be placed so you don't create varying shadows when taking the pictures. Gets rid of video flicker.
Walking: many videos over emphasize stud-by-stud walking which can be painfully slow & rigid to watch. Learn how to move your characters.
Background movement: sliding your background incrementally can help with driving scenes or make us believe something is moving when its not.
Simple math: plan out your framerate ahead of time to help you estimate the # of pics you'll need. Avoid videos that run too slow or fast.
Storyboarding: simple sketches can save you hundreds of hours of unnecessary pictures and keep your story on track.
Onion Skinning: some stop motion apps or software have onion skin tools. These can be a lifesaver if a LEGO piece falls down mid-filming.