This is a small section of one of the quilts for my show. I have quilted some parts of it. I design my own quilting patterns by doodling on paper or in a journal. I tear these out and keep them in a loose stack of papers.
When I am ready to quilt a quilt I get out the stack and look through it and see if there is anything that looks like it will work in any part of the quilt I am quilting. It not, I doodle some more. The doodling just gets my brain and hands working together so I can "draw" the quilting lines on the quilt with my sewing machine.
When I machine quilt I start quilting on the parts I know what I'd like to do with. On this quilt I did the 2 borders with a ribbon type design first. My next area was the 2 diamonds that I quilted long skinny leaves on. I also quilting skinny ribbons on the burgundy and aqua triangles.
I like to quilt with variegated thread. I use both fine and heavy thread. My choice is usually made by what color will be most effective for what I am doing. I will wind a few yards of thread off the spool and lay it on the area I am going to quilt to get an idea how it will look when quilted. I do try to choose a thread has some contrast to the fabric, but not so much that any little irregularity draws your attention.
On this quilt you may have trouble seeing the quilting well. If you click on the photo it will get larger and you may be able to see the quilting better. Had I used thread that was a much greater contrast you would be able to see the quilting much better as well as any irregularities in my stitching.