Here I thought I was clever when I started to store natural peanut butter upside down.
When we open a jar I give it a good stir. If it is really hard on the bottom, I dump it all into the mixer, give it a good mixing then put it back in the jar.
If I open a big jar, I keep it in the fridge after mixing. The small ones get used up so fast that I do not bother with the fridge.
Peanut butter is a food group in my house. Ds eats at least one small (2 cup) jar a week.