You're in. Here's your cheat sheet.
Everything hangs off proportions. Get those right and a scruffy fly still fishes. Get them wrong and the prettiest materials in the world won't save it.
This sheet breaks the whole thing down into six skeletons: upright dry and emerger, nymph, soft hackle, wet fly, streamer, and shaped body. Learn where the parts sit on each one and you can tie almost anything without measuring.
Save it, print it, tape it above your vise. It's yours to keep.
New patterns go up on the channel a few times a week, most built off these same six shapes. Come tie along.