I put 50 HSB in last August that were 6" - 8". I caught one in October that was 12" at least, maybe 13". There may have been a couple that were larger than 8" when they went in, but they do grow quickly.
I have tried a couple of different ways to catch them. All learned on this forum

Tie a pellet in a piece of pantyhose and attach to the hook.
I have used Gulp Alive maggots and I think they see it as a sinking pellet.
I have heard others talk about Stubby Steves. I have not tried these yet, but others on here have had good success.
I have also taken bread and made a doughball on the hook. That works well too.
If you don't use a fly rod, you can simply tie a bobber on to cast the pellet out.
I suggest a circle hook and don't let them take it too long. It is better to miss the strike than to have them swallow the hook.
Have the drag set a little light so you don't get too much pressure on them initially. Hang on! They are fighters!
I think HSB are going to become one of my favorite fish. I love to catch anything, but the HSB I have hooked so far have been a blast.
Good Luck!