If it is staright lines I use painter's tape.There are blue markers that wash out that seem to work well. If it's on a dark fabric I use the pump fine white chalk pencils by Fons & Porter. If it isn't an heirloom quality quilt but a wallhanging or small sewing projects, I use my Frixion pens. There is a lot of debate about these on QB so read it before you decide. Frixion pens are made for paper but the line comes off with friction or an iron. On dark fabric they can bleach the line and if the project gets really cold the line can reappear.
You did not mention if you were machine quilting or hand quilting so I did the hand quilting first.
For machine quilting some like the Golden Thread paper that you stitch through. I like to use the glad press & seal if it's a one off design. Some people stack up layers of tissue paper and stitch through the stack on the design line with an empty machine needle. They pin attach the tissue to the surface of the quilt and follow the perforated line. There are as many methods out there as there are quilter's. Someone else can give you their favourite ways but always, always test whatever method on a scrap first.