I usually use tailors chalk to do most of my markings but I don't like that the fabric likes to slip while I'm marking it. I also use tailor tacks but they take forever. A friend recommended I use Crayola crayons and I can't believe how well they work! The best part is they're super cheap and you can get them everywhere! They also come in an amazing variety of colors - and it's easy to mark white fabric with light yellow. These crayons are designed for kids so they're incredibly easy to wash off. I can usually get rid of my marks with a wet cloth.