I like live skipjacks and shad, next would come fresh cut skips & shad ( fresh- never frozen). Then I'd use frozen skips. That's my order of priority. This fall, it seemed like sometimes shad out produced skips. If the shad are small, we put 3 on a hook. Dave & I both caught some big fish on that, but I seemed to get most of my larger fish on whole skipjacks. I like them fresh-caught the same day, and then I'd fillet off one side of them too.
Of course you can't always get fresh bait. That's why it's good to keep a supply of frozen bait at all times. Even during the season, you can't find the live, so you can bait up with the frozen. I did get my largest fish on frozen cut skipjack.
Goldfish make an excellant bait. They are easy to keep alive & you can get some nices ones in Northside for 50 cents each. I caught my "prize" money fish in the Sept T on a goldfish within 5 minutes of the start ( a 14# flathead).
I was reading where therse guys are experimenting with freezing baits. They are cutting it & using the vacuum seal, but are sealing it in jars vs. bags. They are adding scents, and grinding up the gut sack, heads, gills and adding garlic, etc then freezing it all together. That way all the pieces are soaked. The day you are going fishing, you pull out a jar & let it defrost. You can also use it as a dip bait after you've baited the hooks. They claim it outperforms even fresh bait- tested on channel cats. One advantage the vacuum has is it removes the air & will also force the mixture to penetrate the bait from the pressure. There's one pump that produces 28" of vacuum & comes with the jar attachment. Channels are scavengers, haven't heard much about larger fish caught on it yet. As with any bait, the season & availibility of bait will determine what's best.