I should probably follow this advice with the placemat I'm weaving. I finished the first placemat and am half-way into the second. The first placemat contains many different treadling patterns, in two-inch sections. Also, the warp and weft are almost the same colour. Weft mistakes are difficult to see and I haven't gone looking.
For the second placemat, the one in progress, I picked one treadling pattern and stuck with it. As I wove I saw an occasional pick of weft that didn't pack down as tightly as the rest and I thought it peculiar. When I stopped weaving, I discovered that those spots each had a pick of weft missing in the pattern which means my foot pressed the wrong treadle thereby raising a heddle with the wrong threads. The twill diamonds look squashed.
I could unweave it and reweave applying more concentration and frequent quality control checks. There are threading errors going vertically, though, so taking out the picks of weft would only partially improve the placemat.
In the first placemat, I had to treadle a section of Ms and Ws. For the M you start treadling from the left and head right depressing each of the four treadles by turns. Then you reverse partially, and reverse again, then go back all the way to the left. It's similar to the directions a pen takes when writing the letter M, but done with treadles 1 2 3 4 3 2 3 4 3 2 1. The W follows, 4 3 2 1 2 3 2 1 2 3 4. I got quite lost, repeatedly. I took it with ill grace, too. I suppose ease might come with practice, like learning to drive a manual transmission car. I chose an different pattern for the second placemat, one that was easier and to my eye looked better. I suppose I relaxed my guard.
Oh, for a nice quiet bit of plain weave.
The thing to do, I'm told, is to weave twill in two different colours both for looks and for the way mistakes show up more clearly than they do in monochrome.