I think both are important (regimen & product choice) but
the regimen for me is what really made the difference. I've tried different steps and now that I know what I can and can't do, I keep the same regimen, but switch products.
This has helped me to know what products are working and which ones are not. For example, my regimen is to clarify, then do a HOT, followed by a moisturizing shampoo, porosity treatment, DC, then leave ins.
By sticking to this regimen I know:
A) as much as I love FPS it is too drying for my hair unless I leave it on for less than a minute; however, Roux PC does not dry out my hair.
B) I have fine hair and must clarify weekly or use no silicones at all! and my hair does not like sulfate free shampoos
C) I do not have to rely on Humecto only as my DC; I have found other cheaper products that work just as well if not better.
Finally, because my hair is so fine, I can't prepoo with a creamy conditioner, even if I clarify afterwards. I just end up with a weighed down dry looking hair. So now that I have a regimen that yields my desired results, I stick to it! And I only change/add 1 product at a time.