Once I find a school of Mullet I try to net some using a four foot cast net. Sure you can use a bigger net but from a Yak a four foot net is all you need to catch the bait you will use for the day. To keep them alive I like to keep my finger Mullet in a "Flow Troll" style bait bucket.
But keeping them alive is not always easy, I only put about a dozen or so in a bucket to give them room to move around. If you catch Mullet and they die it's ok you can still use them for bait or you can use them to chum the flat that you are fishing and bring the fish to you.
There are many ways to rig Mullet for flats fishing as well as open water fishing, here are a few ways that I like to rig them. If you are using dead Mullet I like to cut them in half for Redfish and rig them on a 3/0 circle hook with about a two foot section of 20lb monofilament or fluorocarbon leader and a small split shot or just drag a whole Mullet across the bottom on a 1/4 oz jig head for flounder.
When fishing with live Mullet for Redfish or Trout I will rig them in one of these three ways.
Freeling Rig: Take a two foot section of 20lb leader and a Gamakatsu octopus hook or a oct in-line circle hook and simply free line it to allow the Mullet to look as natural as possible. Hook size should change with the size of the bait, for example if you are using a Mullet that is three inches don't rig it with a big hook like a 3/0 because the weight of the hook with wear out the bait quick and the bait will die.
Popping cork rig: uses the same hooks and leader as the freeline rig but adds the cork. This is a great rig when the water is dirty or it's choppy and the fish are having a hard time finding the bait. I like to rig the Mullet in the nose when fishing it under a cork and just give the line a good pull every 30-40 sec.
Fish finder rig: You can use the same hooks listed above or you can use a kahle style hook. For Redfish to run a 1/4 oz egg sinker with a small swivel tied to a 20lb leader about two or three foot long.
Small finger Mullet two - three inches work great for mangrove snapper and flounder and I use the Fish Finder rig but often use a leader up to four feet long for the snapper and a short foot or less section of leader for the flounder. I target these fish around bridges or docks as well as oyster bars on a tide change.
If live bait is not your thing there are plenty of artificial lures that will work just fine this time of year.
Some soft plastic baits to fish when the Mullet are around are the Exude, Berkley Gulp Jerk Shad, or D.O.A Cal Jerkbaits
And if it's hard baits you want to use there here are a few must haves for the tackle box.
I like to start my day really shallow and then work out to the deeper water as the day warms up or start shallow on the flats and move in to the mangrove shorelines to fish the shade. The topwater bite this time of the year is crazy here on my coast but just remember not to set the hook until you feel the fish after the strike. Redfish often miss top water baits because there mouth is on the bottom of there head, but to give yourself a better chance of hooking up I like to add a little weight to the back of the bait. This will let the tail end of the bait drop down a little deeper so the Redfish doesn't have to roll on top of it as much.
I hope this helps you find and catch more fish this Spring into Summer.