I have stumbled across a product that’s working well for my fine hair without weighing it down, and wanted to share here in case anyone else wants to give it a whirl!
Lador Keratin Power Glue — it’s a leave-in product. I’ve been using Lador shampoos for years and both my teen and I really like them, despite having very different hair. It’s cheapest on YesStyle.com, but that’s a whole “thing” because it’s drop-shipped from Hong Kong. They have it on Amazon for just a couple of dollars more ($18ish):
LA'DOR Keratin Power Glue 5.3 Oz Deep Repair Damage Hair Dry Damaged Color Treated Hair Deep Conditioner Protein Keratin complex
https://a.co/d/4q2qcvI
It contains dimethicone, which normally I might avoid, but it hasn’t weighed down/coated/greased up my fine hair the way those products usually do.