I used parchment paper when I did a Celtic Knot wall hanging. Traced the pattern on parchment, then lightly ironed my bias strips to the pattern. When I was finished, I could gently pick up the whole piece and position it on the fabric. Because of the over/under action that is part of the design and ironing (as I constructed it), the celtic knot was pretty much done. Nothing stuck to it and it was easy to adjust as needed. This is a link to a previous post (with pictures).
http://www.quiltingboard.com/t-62229-2.htm#1519028