I have noticed in higher dews, it is more difficult for myself to achieve beyond 2 day hair. But in lower dews I have been achieving 6 day hair. I believe, as other posters have stated, that what you do on wash day will be the basis of how your hair will be for the next few days.

My advice is merely more of styling. I won't give any suggestions for products since that is a hit and miss. We all have different hair. I think making sure you section your hair, when wet, and applying your product throughly, truly helps make sure each curl is captured and moisturized.

At night, I think pineappling is a great method. However, I pineapple and also use a scarf on top to ensure that my hair isn't roughed around. In addition, applying a little water (using a spray bottle) and then a little sealer (such as coconut oil or olive oil) and then pineappling, has assisted my hair to lessen with frizz and keeps it refreshed to last longer. Also, manipulating it less when it's in its dry state has also helped make my hair last longer.

Hope some of these suggestions help.
High Porosity, Fine, Thin Density, Low Elasticity
Co-wash, leave in, and gel: Alba botanica coconut cond., ogx mousse, &/or super wet look gel.
Curls