You might want to search prior posts about the Fixon pen and the problems it can cause

I use a white pencil with dark fabric and a good old mechanical pencil with light fabric, it all come out in the wash

Thanks for posting this question. I often wonder what others use. I've been trying them all. I have to buy a Frixion now.

I use these as well...

Ditto. I love them.

black graphit pens ----- try "Sketch and Wash" made by General Pencil Co. Can get them in some quilt shops or art supply store and probably Michaels and even JoAnn in their are pencil section

I use frixion pen but my all time favorite is spray chalk. It goes on easily and stays on while you are quilting, unlike pounch chalk.
Also comes off with a damp cloth. On the negitive side- it is a little messy, but so worth it, I use it all the time.

I like the disappearing marker that is a combo with the blue, the purple comes out in 20 minutes to 24 hours and the blue disappears with a touch of water.

Chalk or the pounce which uses chalk; you can spray it lightly with hairspray to make it last longer. I've used a sliver of soap and that worked good as well. If you use the blue pen make sure you don't get heat on it because it'll set in in and then you have to soak it to keep it from coming back. If you just run water over it it'll disapear but will come back later. I always soak mine for a while to prevent it form coming back.

Right now I'm using the Sewline ceramic pencil and so far I love it. I'm using the green "lead" and it erases pretty well, mostly came out with blotting with a damp cloth, so I believe it will come out with a launder. Nice fine line. They have white, green, pink and "graphite" colors, so you should be able to make about any color fabric. The pencil is a bit pricey (I think I pad $16 for mine in Shipshewana), but I think if you shop around you could do a little better. The "lead" refills are sold wherever the pencils are sold.