What I have a lot of success with is ring potting. A steel ring (bike rims work too) about 3ft in diameter with a net on the bottom. Similar to what yakkaman described earlier. Like a big landing net but without the handle. 3 point saddle for keeping it level on the drop and lift. Tie lots of bait (usually a couple of cod bodies or similar) in the bottom drop them down to soak for about 20 minutes and haul them up, bingo. Best lift for 1 pot was 13 crays, but only 4 were keepers, bugger.

The catch, yes there is one with this method. As crays become active at dusk, you need to be prepared to be on the water at night, in the dark! Not possible around a lot of our coastline and I only do it on nice calm nights. In saying that you do not need to go far. The main spot I go to I would be no more than 100m from the beach and in 2-10m of water. At New Year most of the crays I got were in 2-4m of water. I usually go out for a couple of hours max and it is a rare occasion when I go back to shore without my quota. I have 3 of these pots and drop them at about 5 minute intervals and then all you do is paddle a little circuit lifting the pots. 

Essential equipment

Headlamp - for getting the little buggers out of the net

Glow Sticks - tape one to each bouy, makes them a lot easier to find in a swell

Measure - I find I get quite a few shorties so measure them on the water

Catch Bag - or something to put your catch in (an old sack works)

Fishfinder - great for picking drop offs/shelfs where the little buggers might be hiding

Yak and paddle are helpful too

Sorry Orca & Nuke Chook, our secret is out, but its too good not to share. And when I say "I" you know I mean "we"