How not to blister?

Any recommendations on how best to avoid getting blisters on your feet? 

I have tried both Balega high cushion socks and Feetures high cushion socks, but I’m still getting massive blisters on the inside/ball of my feet. 

Those socks work just fine for 3 or 4 mile runs, but for my long runs, I can’t seem to do anything to avoid getting blisters all over my feet…help?