We're about the same age & have the same hair type (though I'm more on the 4b side), and, I *heart* just about every Motions product I've come across. Personally, I stick with their products that aren't texture-specific, but, I've heard nothing but good things about their new Naturally You products.
I'm a bit of a product mixtress (I have to be - I have no job!), so, I have a "serum" that I make, but, it's on my blog. Anywho, I my favorite moisturizing product is the good, old-fashioned grease that I used when I was relaxed (it's not bad for your hair, as long as you're smart about using it), along with water and leave-in conditioner (Motions Nourishing leave-in).
Because my hair is so thick, I'm extra sure to pull it tight; not tight enough to break it (I'm transitioning after all), but, because 4b hair is prone to shrinkage, I pull it tight enough to all it to hold the different protective styles I like doing (mainly bantu knots & French Braids.
My favorite "trick" is water. I know that's every natural/transitioning lady's trick, but, I notice that with my 4b hair it is MUCH easier to style and deal with when wet (then again, it could be because I've still got relaxed hair in there), though, it must be detangled properly (and, a liberal amount of the leave-in is key when detangling, especially because it's prone to shrinkage and, thus, tangling).
And, before bed, I just throw it back in braids (either the loose braids we did as a child on our dolls or French Braids) and let it be.
Hope I helped.