I have fine hair and also get OC'd easily. I agree with Tresemme Naturals Radiant Volume - I use for a co-wash and have used as a LI (it also smells great IMO). I use Garnier Fructis Sleek and Shine (just a dime-sized amount) as a leave in and it make detangling a breeze! Goodluck!
2b/3a fine/med-hi density/high porosity (I think)/ highlight-no silicones/sulfates
Lo-poo - ABBA Gentle Shampoo/ Shea Moisture Curl & Shine
Conditioner: GVCB (love it!)/ Regis OO
Leave in: As I Am
Co-Wash: Tresemme or DevaCurl NoPoo
Stylers: As I Am Curling Jelly/GF Pure Clean/ LALCurl gel - all with BRHG added
Style: scrunch/ diffuse, then air dry. I don't Have much frizz at all