Here’s a few videos where you can start:

MAV vs. Loew-Cornell

MAC 239 vs. MAC 217 vs. MAC 224 vs. Loew-Cornell

If you’re vegan, though, you’re out of luck. I don’t know any of the synthetic brushes that Loew-Cornell produces (they do have a synthetic range). Synthetic bristles are good for liquid foundation and that’s about it.

When you go to the craft store, you want to look for goat or squirrel hair for bristles as that what MAC uses. The best places are craft stores geared for crafts (like Michaels) and not for fabric (JoAnns). There’s greater selection. Pig hair is far too harsh. I’m not sure about horsetail hair though. Horsehair typically is normally reserved for high-quality, uber-expensive paintbrushes. Talkon bristles typically equates expensive as well.

Some people do state that paint brushes are only for paints and make-up brushes are only for make-up, but MAC uses the EXACT same bristles that Loew-Cornell uses. Bristles aren’t like paint, where they can be suited for only certain items (semi-gloss, eggshell, latex, etc.). It’s preference based mainly. I like natural over synthetic and longer handles than shorter handles.