Lynne has asked me about the pink wriggly row counter I mentioned here. This isn't my own idea, but one that I got from a website a few years ago when I first started surfing knitting websites. I've looked for it today but I can't find it.
As I said, I can't be relied upon to turn one of those little row counters that slides on to the needle, and although I'm a little better with five-bar gates I'm still not very good. I bought a clicker at one point and that was quite good for a while but then I sort of trailed off and forgot about that. I know you can get those clever bangles that have numbered beads on them, but I would probably still forget that after the novelty had worn off.
The beauty of this is that it sits on the needle between stitches, so you can't miss it. When you reach it, you slip the next loop on to the needle, so when you get to the last loop you know it's time to start again. When I'm shaping a sleeve, I'll have a four-row one and a six-row one and so on, and I can relax. I like to make them out of a yarn which contrasts very sharply, so that I don't knit them into the thing I'm knitting while I stare glassy-eyed at the television.
You need a piece of yarn longer than you think you'll need. Nowadays I always make them on one of the needles I'm going to use, ever since the time I made a very long one and then discovered that the loops were too small. Sigh.