No matter what kind of fish you are after, you will need some kind of bait to tempt it onto your hook. So what is the best kind of bait? Much depends on the kind of fish you are after. The main difference in bait is whether it is live or artificial. Many anglers prefer to use live bait, but the downside is its cost and the time it takes to rebait your hook when you lose it - time that could be better spent in the actual fishing. Another problem could be in keeping it alive while you are fishing.
Having spent money on live bait, you don't want to see it dead before your fishing trip is over. If you are on a boat there may be a live well to keep the bait in, or some other special container that will move and aerate the water, thus keeping the bait alive until you need it.
Gray trout of weakfish can be caught with long thin strips of squid. Of course, this won't be alive, but will need to be kept fresh in a cooler. It should be cut into strips of about 2 inches long and half an inch wide. Make sure it dangles off your hooks- that is, hook one end so you have a long, dangly piece to float around in the water.
In some areas, shrimp or peeler crab are used to even greater advantage. Asking at a bait shop will give you lots of handy information about what is best in your area. Some people use minnows and they can be real or artificial ones.
For freshwater mullet, worms can be dug out of the garden for bait. The advantage of this is that they are free and if you don't use them all, they can go back in the garden for next time. Perch will often take crickets or white curly grubs found under logs by the riverbank. Worms and crickets can be kept for a day in a bait bucket or a bait cup that can be attached to your belt for ease of use. If using a bucket, keep it in a shady spot with some moist earth in it to keep the worms happy.
The good thing about using artificial bait is that it isn't as likely to be lost, so that your initial outlay to buy it will be repaid over and over as you catch many fish on the same one. Of course, occasionally there may be a loss, but this will happen no matter what bait you use. If you go on a package fishing trip, the best bait to use will likely be provided.