Best way what i know currently is to get a pickaxe and head to diamond mine. Mine some diamonds and drop em soon as your backpack is full. Keep on farming and you will be on max lvl in literally no time.
It is just more enjoyable to w8 for those lvl's to come.
I mine copper full hobo style and give it to the hobos who come and when they ask why im just giving away everything i mine i say it is for life experience.