I don't have proper character sheets for my characters because I have so many of them and they change outfits quite often. Instead I have quick sketches of all the outfits and colour maps that I use instead. I've also had most of my characters for a long time, so I've gotten very used to drawing them by now, so character sheets don't really feel like a necessity to me.
References are useful when there's a lot to remember but I don't think in comics they need to be as detailed as say, in animation. Especially if there's only one artist and it's you.