As much as we all want healthy hair... The key is retaining the length and that is done through keeping your hair healthy. and this is how I do it.
Daily : Moisturize ( Water based moisturiser) and seal hair with an oil and scalp massages every 3 days
weekly: Full wash day Shampoo, Deep Conditioning, leave ins
Monthly: Protein treatments and Clarifying shampoo
Quarterly:Relax day.
Protective styles every now and then to give my hair a rest (Braids, weave, corn rows)

these are just the basics to achieving healthy hair. it is hard work but it is totally worth it.

I have seen so much progress through these methods... hope this was helpful