I had absolutely *horrendous* frizz too and could not figure it out! I was switching from one 'poo/condish to the next in desperation...there are a few things that stopped my frizz, along with all the other things you mentioned you were doing (I am taking those steps too).
This is what works for me, I can't swear it will for you, but I really feel your pain, lol! My few tricks are: leaving my condish in while I do my other shower stuff and putting my hair in a shower cap, then using the right layering of products for *my* hair, along with the super-soaker method (check out the forum stickies on methods, I think there are links at the top of the general hair topics page, as well as in the Newbies forum) I watched how Rudeechick did her hair in her super-soaker video and did the same thing, and voila, no more frizz! (or very little of it, anyways!) Better curl/clump formation too.
I think the reason this works is that using a Denman style brush after a base coat of leave-in condish and pre-styler, as Rudeec does, makes the hair stick together more in clumps, and so it binds in all those hairs that split away and want to frizz, back into the clump matrix, lol! Almost as though the Denman puts each hair back where it should be neatly. After I do this, I put my styling product in my soaking hair, re-wet it a little more, then I plop hair once, soaking wet, in a cotton t-shirt, for about the time it takes me to brush my teeth, then I remove that, and I scrunch the wet hair with another cotton t-shirt to encourage my curls and get some more of the water out. Then I replop in a third cotton t-shirt for about 5 mins.
I blow dry my hair (low heat and low fan speed) using the pixiecurl method with the diffuser, and during my final scrunching of the dry hair (to remove gel hardness or gel cast) I wear common kitchen rubber gloves so as not to ruffle the cuticles too much. And voila. Frizz-free hair
For me, this is nothing short of a miracle! I think the combination of the steps I take is what reduced my frizz so very drastically...I also have a much better curl pattern too because of the super-soaker method.
This really does work for me, I hope it works for you too. I know Rudeec uses natural products, (I don't ;p I love my cones, lol!) and she is always frizz-free too, with lovely formed clumps, so it must be her method that works so well! The more times I use this method, the less and less frizz I have. I also know that many curlies who live in humid conditions use a layer of glycerin-type product in their hair (Like CHS Curl Keeper) after their leave-in condish, that seems to help them a lot. It depends on your hair, I guess, because everyone is soooo different!
I hope this helps!
ETA: If you don't like to blow-dry, you can help your roots by drying your hair in a pineapple, or use hair clips along your root line to make them dry higher, so you won't get flat top
Finer, mixed with coarser strands, low-porosity, wavy curly whirly hair...3A, 2C hair. Medium thickness, medium elasticity.
S-shaped hair with corkscrew ends. My hair is even more confused than me ;p
My hair officially hates protein
Once a month is enough!
Currently a fan of TiGi products, (rock on, TiGi Curlesque styling creme!) but that will soon change - I am a self-avowed product junkie! Yay!
BIG fan of supersoaker method - thanks Rudeechick!