Without a computer control, there will always be wonky spots. Places where seams butt, or corners that are thicker. I can seldom do a perfect curve, or at least the curve I had planned. You learn to avoid those spots and do patterns that aren't so precise. Meandering gets easier, but I find by the time I get to the other size of a Queen, I've often forgotten what size of meander I started with. My customers know that I can't do "perfect complex" and they're happy with the style I do. I bought some thick acrylic rulers to help me do precise straight lines but beyond that my work is pretty open.
MaryKatherine