I knit and crochet. Use the loop-style markers if you want to move them easily. They can fall out, but are easier to move than safety-pin types. Even a small strand of opposite-color yarn can be quickly stitched or looped through that first stitch, and it's more likely to stay in place, though not as fun being so damned frugal at the yarn store (yes! you do need all those fun markers, and I promise not to let anyone's dp know there might be another way! Go on and buy them becuase I looove opening up my goody box and seeing all those cool little tools! Happyhappyhappy.....) You can pull out the yarn when you're done. You could move it, or leave it in and add another one. But that's so boring and practical.
It's been a couple of months, how's it going?