Bonus Tip: Name Your Fingerprints.
This won’t make the fingerprint reader more accurate, but it’s still a good thing to do. Both iOS and Android let you give your fingerprints specific names, which is better than fingerprint 1, 2, etc.
When you name them, you can easily tell what is what. That way, if you ever forget whether you’ve registered a particular finger, you’ll be able to tell pretty quickly. And if you have the fingerprints of multiple people registered, it makes them much easier to tell apart.