I'm no knitter. My wife? My wife's a knitter. The process is 1) Knit a test swatch so you can see how it reacts to your needles and ensure you have enough yarn 2) knit the whole thing 3) wet block it 4) Give it to whatever friend or relative it was promised to I encourage you to keep on "just doing" but I will also say that a little planning ahead of time will radically increase your satisfaction with the finished product. Mixing different fibers is going to induce a wretched nonlinearity into your project. My wife won't even mix different batches of the same yarn; the colors shift.
Yeah. As a medium, yarn is probably the most frustrating I've ever worked with, so kudos to both our wives for putting up with it. I totally never intended to use wool, knowing it would pull a stunt like this, bit fortunately, for my next phase, I have yarn with the wrappers still and they're all acrylic. It's funny, cause this whole thing is more about doing than results, but I still care a little about the results. That said, I'm kind of intrigued by the wool fusing to everything and what it might do for repair work, so I'm gonna keep that property running in the back of my head and see if I can't come up with some ideas and experiments.