Mullet are usually found in shallow water, over sand banks, though at times I have caught them near the surface of deeper water.
Bread for burley and bread for bait. A few small pieces that float along in the current will bring them on the bite, also a small piece of bread that is mashed up and thrown out to slowly sink. Floating bread crusts will also attract bream and garfish (very occasionally a blackfish). Floating bread also attracts *&#@*#* seagulls, that will swoop down to eat the bread and scare off the mullet.
I use half a piece of fresh bread in the hand, dip it into the water for a second then squeeze out some water. Squeeze out a lot of water and the bread becomes a bit doughy, squeeze out less water and the bread is a bit softer. Mould a piece of a size less than a 5 cent piece - size 8 or 10 hook - and lob it out near the floating bread burley - hard to throw it against any wind, but you can use a small bubble float to gain distance. The best idea is to anchor or fish up wind so that the wind can assist with casting.
Mullet will also eat squirt worms, small pieces of prawn, dough made from flour.