To me, 2nd day (or multi-day) hair means hair which you didn't have to saturate with water and restyle. I routinely get multi-day hair, and never more than dampen my hair to do that. I was not able to do this for quite a while after going CG. That's partially because mainstream hair products (chocked full of silicones) had convinced me that I had to get my hair so wet all the curl was pulled out, and it always seemed like I might as well just go ahead and rewash it at that point. After that, it was mostly learning curve, and trying new things.

Things that help:

a silk (not satin polyester) pillowcase

sweeping my hair up toward the head of the bed as I lay my head down
scrunching my hair as I lay my head down

spraying my hands, never my hair with water or refreshing spray

dampening my hair with my hands by sandwiching my hair between my hands then running them down from root to tip, scrunching, scrubbing my roots

smoothing a light gel over my hair and scrunching when I start getting ready for bed

using a Q-Redew vapour wand to steam my hair

Baby Fine 3B, low porosity, normal density and elasticity
CGing since July 2008