I have used the crayola markers too. I made a heirloom christening gown, and marked the center in yellow. I just know it didn't come out. I must have ironed it. I have used a sharp mechanical pencil too. On light colored fabric it works well. In applique by the time you get the piece appliqued a great deal has already worn off. I got a frixon pen for christmas and am looking forward to using it. I took a Shar Pederson class at quilt festival and it was on navy fabric. She had a white pen that we used--i would have to go and see if I can find it to tell you the name, but when you iron it it comes off. I have used silver water color pencils (and yellow) for marking quilts on black. It works well.
I think it best to experiment and try different methods and see what works best for you. Chalk for me doesn't last very long, so I try and do this right before I quilt.
Oh, and I also got a mechcanical pencil that erases as well as washing out.