Lauraloo-you have some amazing hair girl!
I agree, whatever you are using seems to definitely work for you. As far as the new "it" products, I personally have been daydreaming of purchasing and using AG re-coil curl enhancer because of everyone's raves (fine and course hairs alike). I am curious, what is your routine, and how do you have such defined, yet soft looking hair? I seem to rarely get both at the same time

On another note, to help you w/ volume I strongly recommend Aveda Sap Moss Styling Spray. I have been using it for over a year w/ great results. It has the consistancy of a spray gel. I spray it on my roots after applying my other products and diffuse upside down. It gives great volume, and gives me ropey curls close to the root. I also use it while diffusing to spot treat areas that need more curl definition or are frizzy. It is my HG magic potion in a bottle. Mousses are great for more volume as well, and many are raving about the Joico one here, but I have never tried it. I personally love Paul Mitchell Sculpting Foam med. hold, but I know there is also an extra body formula. Both the Aveda and PM have water soluable cone(s).

Winter Routine
Co-wash: Hair One Argan Oil or Burt's Bees GreenTea and Fennel
Low-Po: Devacurl LP or SheaMoisture Black Soap(1-2x/wk)
Condish: SheaMoisture Deep Repair Mask
Leave-in: Kinky Curly Knot Today AND
Styler: GF Curl Construct Mousse or Biotera gel
-Diffuser happy!
Treatments: Oils or butters,and trying out Aubrey Organics GPB for protein