Lab scans are getting expensive, so I tried digitising a few rolls at home. The setup:
Lock focus and exposure on the frame, shoot in RAW if the phone allows it, and turn off any "scene" processing. Dust is the biggest enemy: a blower brush before every strip saves a lot of retouching later.
Colour negatives need inverting and a lot of white balance fiddling. Black and white is far easier and honestly looks great this way.