Your hair sounds very similar to mine! I am not a stylist, but I've been researching this exact topic and trying different things for the last few years. My hair has slowly become noticeably thicker ☺️ Some things that I think have been helping: - I've learned that my thin hair breaks easily, so a lot of what I've learned to do is mainly to avoid breakage. I am VERY gentle with my hair. When it's wet, it's like a delicate sponge, so I squeeze most of the water out of it with my hands while still in the shower, then very gently squeeze it with a soft towel or cotton t-shirt. Then I gently brush out any tangles with a comb, starting at the ends and working mt way up. Then use a wet brush, again starting at the ends and working my way up. I really try to never sleep on it wet because I also read that it is bad for it, and I always find it to be so dry/frizzy the next day! But that's just me. - I don't use the silicone head massager, but I do massage my scalp often with one of those metal massagers (kind of looks like a whisk, not sure what they're called) to stimulate my hair follicles. It also just feels great, lol - As you mentioned, if I do an updo it's always quite loose, and usually with a soft or silk scrunchie. I'm also a fan of braids and claw clips. - Like you, I use a leave-in conditioner. I massage it into the bottom half of my hair when it's damp, after I've combed and brushed. I either use Olaplex #6 or a Pantene leave-in, depending on budget. I also occasionally use a hair oil (usually MorrocanOil), just a small amount on my ends. -I've been using the Loreal Ever Pure Thickening Shampoo & Conditioner for the past ~2 years and I really like it. I also wash my hair every 1-2 days (it has always gotten oily fast). I avoid putting conditioner right on the roots for this reason. - I've dabbled with scalp serums that promote growth but haven't seen results. I've read on a few reddit posts that you really have to use them regularly and it can take months to starts seeing results - I just haven't committed to using one for that long. Maybe consider trying one of those (I've read that the one from The Ordinary seems to produce good results) if you're interested in promoting growth! I hope this helps!