Basically, I completed the Knight Waves and got 70 prayer. I was wondering about some basic uses for Piety. Should I use it on Slayer tasks? Flash or use prayer pots? I just need to know how to use it. Thanks in advance!

Use it whenever you melee. You can choose to flash if you feel up to it, or use prayer potions.

Ask yourself:

1) Am I using melee?

2) Would improved att, str and def increase my kill rate? (Give ya hint for this one it is never ever no; other than pointless weak monsters)

3) Can I sacrifice space for prayer pots (or am right by an altar)?

 

When you answer yes to all 3 use piety.