the fastest way to get legends, from my experience, is to have an imp for a pet, set it to legend + for pick ups, and you will end up with a lot of legends to turn into dust. if you don't have a lot of gold find affix, you will run out of gold.
I ended up using the random drops I got to learn how to craft items, and between random drops and the DQ Forums, I got some good ideas to help me farm and melt monsters.
I decided to focus on Ascending for experience, and after I get the sixth Perk, I'll focus on a good farming build to get the loot I need to make good gears. I tried doing it all at once, and didn't get very far, so taking it in stages is helping me.