Capture the footage in 4Kor better (2K will do in a pinch) because it's harder to save a blurry image
Use a tripod and high-quality external microphone with plenty of breathing room
Use a disk cleaner app like Disk Speed Test, which can help detect read errors on your hard drive
Cut out any camera shake or other moving objects unless you want that effect for special effects
Save all versions of every clip - there are lots of editing options out there that might not work as well if you're missing a few key elements from a previous version.