Okay I just decided to share a few tips about mining that help me bring in big loads of ores and such.

1. When you go mining bring a lot of pickaxes, torches, and some food.
2. Mine at the y cord 14 just tunnel because that's where the most ores are.
3. If you're by lava and see an ore near the lava even if there's a one block place you can stand on make it bigger so that you don't fall into the lava.
4. NEVER mine a block out from underneath you.
5. If you're on a cliff with lava below it ether go home and drop your load off or put a chest down with your load in it so that you won't lose everything if you fall into the lava.

I hope these mining tips helped you. :D