Shampooing: I find alternating works best, though I will never know why. I use Kerastase Bain Satin Shampoo #2 and Rene Furterer Okara Protect Color Radiance Shampoo. I also try my damnedest to only wash my hair every other day. To keep my hair fluffy on the "other" days, I use Rene Furterer Dry Shampoo. Believe me, I've tried to find a better dry shampoo, but have yet to find any that compare.
Conditioning: For whatever reason, VO5 Strawberries and Cream conditioner seems to work the best for me. Every hair instinct tells me a $1 conditioner could not possibly be the best, but it keeps my hair voluminous and under control better than anything else I've tried.
Treatment: I do a VO5 Hot Oil Treatment and Rene Furterer Karite Nourishing Conditioning Cream mask, each once a week.
Styling: Contrary to logic, less is more, especially when one has less to work with. I tried "super-volumizing" products in the past and all they do is weigh my hair down. I use Bumble & Bumble thickening spray on the roots with some sort of heat-protective lotion/cream on the ends (I love Kerastase Creme Nutri-Sculpt). After applying product, I blow-dry the Hell out of it with a Goody Ouchless Ceramic round brush, then stand in front of the air-conditioner to set it (sounds bizarre, but this step is key).
Probably seems like a lot of stuff, but you'd be surprised how rarely you have to replace products when you use them sparingly :-)
images via Amazon, Bumble & Bumble, Sephora and Drugstore.com