I think when you're writing patterns, you should write them as if the quilter is a beginner, and here is why I think that:
Most experienced quilters will skip right over the general instructions that are usually given at the front of the pattern, such as "sew all seams at 1/4" inch, because they already know that. Experienced quilters can also figure out different or preferred ways of assembly on their own. However, new quilters often don't know that. My mom was a garment sewist, not professional, but sewed enough to make blouses for herself, pillowcase dresses for her church charity, etc. She was invited to join a round robin. I told her I didn't think it was the best choice for a beginner quilter, but she really wanted to do it, so I told her I would help and she could ask questions, etc. Well, she didn't know what she didn't know, didn't ask me the right questions, sewed all her seams with a 5/8" seam, and the other members of the round robin were both mad at her and laughed her. (Then, because they were mean to my mama, I had to go kick all of their... never mind.
) Fortunately she didn't let that experience stop her and she still quilts.
My point is, write and explain everything in detail. It won't hurt experienced quilters and will help beginners.
eta: One of the things I hear most from both beginning and experienced quilters is how they wished patterns would give fabric requirements for multiple sizes of quilts. Obviously you can't do that for all quilt patterns, but for those that are easily scalable, I think is a good idea.