Used a high-quality asset (I use Unity) but also I found that found footage post-processing hides mistakes lol. When things are grainy it tends to mesh assets together so you don't have to worry about asset mismatch.
When it comes to audio I used another Unity asset that helps with blending audio like outside -> inside. Also making random 3D sounds like when the wendigo surrounds you.
I'm sure there are unreal equivalents. I'm excited to see what you make next!