I'm just like you... I have to work at figuring out what sort of quilting design I want to use. I generally doodle to figure it out.
I begin by putting a piece of the clear upholstery vinyl (or other heavy-ish clear plastic) over the quilt I am working on. I doodle quilt designs with my ultra-fine point Sharpie on the plastic, which is laid over the quilt. (In this photo the doodled-on plastic is pinned to my design wall so that the picture is clearer.)
You can see how close I came to the edges of the plastic with my Sharpie. I'm not always as careful as I should be. If you are smarter than me, you'll cut your plastic bigger so that you do not run the risk of drawing on your quilt with a permanent marker.
In this example, the center flower was easy to come up with. Harder to decide on was the fill outside of the flower, mostly in the corners. I like the way this quilting design turned out.
FYI - If you hire someone to quilt your tops, this is an excellent way to share ideas with your quilter. Even if you don't draw well, you can doodle something that will help get your intentions across.