I suggest you learn to draw very convincing figures out of your head. It is easier than you think, as long as you take small steps and stay with it for a long time.
When I was fifteen and sixteen, I drew hundreds of figures in pencil, most fairly small. I was inspired by Andrew Loomis and by Daumier (his wiggly line.)
I gradually took into account proper proportions. When I wanted to develop a form in a pose that I didn't understand, I would study that, draw it until I had it in my mind. I never used a mannikin. When I got one for Christmas, I never took to it.
I have only used my Spiderman figures for pose ideas and only rarely at that.