Hello, I'm thinking of getting a cast net to start catching my own bait. I usually just bring out the light equipment and catch them one by one, but that gets very tedious at times, and sometimes I'd rather not do that. So, since I'll be new at this, any recommendations for size?

some will disagree, but I would suggest you start with the largest legal (7' radius). Utilize you-tube and your yard to learn one of the multiple techniques and figure out which works best for you. Practice in your yard until you have it down. Good all around mesh size is 3/8".

Get a small, inexpensive net to practice with, say 3-1/2 radius. It'll be much easier to learn how to throw it so it opens fully, and you'll still be able to catch bait with it.

Once you're proficient with the smaller net, then spend the big bucks on a 5 to 7 foot net (I mean radius, so a 7 foot radius net is 14 feet in diameter, which is the maximum allowed in Texas).

Trying to learn with a heavier, larger net will wear you out and you can hurt yourself in really interesting ways.

If you have trouble throwing the net properly just get one of these throw rings. They work.
http://perfectcirclenetthrower.com/HTML/products.htm

The largest legal net is a 7' radius, but they can be tough to learn to throw. Part of the reason is that every net maker puts a different amount of lead on the rim. Some want a fast falling net and others need an average sinker.

Find a friend and try a few before you spend too much. You don't need a really expensive model, at some point in freshwater you will drop it on a stump and tear it up.

I have bought many castnets that do not do the job well. Buy a 7 foot net from Tim Wade in FL. Hand made and best I've ever owned. Google Tim wade nets and you can find his contact info and will speak directly to him. Once you get it practice practice practice. Once your throwing pancakes in your backyard your good to go!