Purging is definitely the most important part.. but the crab boil Zattarain is my favorite, make sure you have enough Crab boil for the pounds Of Crawfish. put the crab boil in your pot with water, whole onion and the garlic clove, bring it to a boil-for 5 minuets... Then add New potatoes, lemons cut in half and two packages of mushrooms bring to boil-5 minutes, then add corn bugs and a whole stick of butter boil for 2-5 minutes then let them set for 20 minuets.
Let's say I got 25lbs of bugs I'm gonna have 2 onions two garlic 3 lbs of new potatoes 12 small corns, 3 big lemons, two packages of mushrooms and a sick of butter....You can add and take away ingredients but always purge, plenty of crab boil and butter, and a long soak time.