I know all about the frizzy! I've got some very curly hair, and it's taken me a LONG time to learn how to deal with it.
First off, I'd recommend some kind of de-frizzing serum- it actually does work, and it's really nice on your hair. Put it on right after you shower.
Next, don't wash it, or only wash with conditioner. I really balked at this one for a long time- I was like "Eeeeww!" because...honestly, not washing your hair? Gross! But, since I cut my hair short, I started going for longer amounts of time without washing, and getting nicer and nicer results from it. I now wash my hair about once a month. Yes, some people would say that's gross- I do get it wet in the shower every day. However, this helps with the frizzing problem because curly hair is naturally dry, and shampoo (even conditioner) can strip it of all it's oils, and it ends up being extra dry! So, don't wash it. Srsly.
I can actually go 10 days without getting my hair wet, washing, or anything, before it even starts to look gross. How's that for dry hair?
Next, if you can't find a good curl serum, or if you find they don't work well enough, try some other hair products. I used to use a moose, a kind of gel thing (I think it was called a souffle, but it was basically like a soft gel), and sometimes a bit of serum, if I had it. This worked really well for me!
Other tips are things like NEVER brush your hair! Don't even think about it! Unless you're pulling it back, a brush shouldn't even get near it. Just run your fingers through it in the shower, only when it's wet, and get the tangles out that way.
When your hair is wet, put your product in, and then leave it alone! Don't play with it or fiddle, or even swish it too much! lol. Curly hair looks it's best when it can settle down and just curl.
What goes on with your hair when it turns frizzy is all of your curl, just...taken apart. Curls are made up of a thousand hairs that all curl together, and then they stay like that! So, if you pull all those hairs apart, and they dry like that (or even when it's already dry) they won't go back into the big curl, but they're not gonna go straight, either! So, you get the frizzyness.
As for increasing your curl-factor, I would say...hot rollers have really worked for me, and curling irons. Be sure to get yourself some kind of hair-protector, because it'll dry out your already-dry hair! And, if you go to a salon, they'll sometimes straighten your hair first, and then put it in curlers- this never, ever worked for me! My hair accepts ONE instruction after being wet, and that's IT. So, try the curlers directly after getting your hair wet instead- I came out with crazy-awesome ringlets!
Best of luck to you! I hope it all goes really well!