WL fine lady checking in. Great thread!
ELIMINATE/REDUCE SOURCES OF DAMAGE
This has been the biggest reason for me being able to grow longer hair. I have been stuck at various lengths in my life- NL, SL/CBL, APL, BSL. These (esp the top 2) are what kept me stuck at all but the last one:
Heat: Flat ironing/blowdrying are death for my hair. My avi is flat ironed (which I did on the lowest heat w/ 1 pass & heat protectant). I did that once in my 3 year journey. I most likely won't flat iron again for years, if ever (I'll rollerset if I want straightish hair). If I really had to flat iron, I would limit it to 1-2x/year, tops. Use airdryed styles or rollersets with a hood dryer instead.
Chemicals: Going natural was huge for me. Color, especially coloring lighter, was unnecessary damage. Also, for growing long hair, you would have to chop or have 2-tone hair for years if you change your mind.
Mechanical Damage: No brushes (too harsh for fine hair). Gentle combing from the bottom up in sections. Seamless widetooth comb (Magic Star Jumbo Rake). No bobby pins (hairpins instead). No buns w/ ends caught in a ponytail holder. Rarely using ponytail holders, opting for hairpins instead.
PROTECTIVE STYLING
Tuck the Ends: A good PS involves tucked-in ends. Braids, for example, keep the hair from tangling on itself (more important the higher your hairtype & shrinkage). But unless the ends are also tucked, they aren't fully protective.
Getting to APL: If your hair falls from NL to CBL while "out", PS like your life depends on it past these lengths. The constant rubbing of your ends on your shoulders will wear them off!
PSing while enjoying your hair: I wear my hair out for "max enjoyment" only. Meaning, I almost always have my hair up in a simple (but cute) low, loose side bun at home or other times I don't care about. At night, I put it in a bun on top of my head, or 3 braids (which I then gently coil on themselves & tuck the ends). I only wear it out outside when it's not windy or cold.
I only wear it out when it looks fabulous (although as my hair has gotten longer, this is happening much more frequently!). So, I might wear my hair out 10 hours in a week, but it's the 10 hours I care most about looking good for. If I notice my ends are feeling dry, I immediately make an effort to actively PS.
Kimmaytube's routine of wearing twists during the week then wearing a twistout during the weekend would be a good reggie for those who do medium term PS.
PRODUCT BUILDUP
This was a big problem for me. I got out of the buildup/remove routine and now I just use mud wash, butters/oils, AVG, and moisturize w/ water.
SENSIBLE TRIMMING
I needed to trim more frequently while I was transitioning and growing out damage. Now, I am trimming every 3-6 months (using the Morrocco Method calendar). IMO 6-8 weeks if you want longer hair is too frequent for even fine hair that isn't damaged and isn't getting tons of heat, etc.