I've been sewing for 40 plus years. Made all my clothes, kid clothes, curtains, swimsuits, wedding clothes, a full nursery layette, even made my husband a suit once! So I knew my way around a sewing machine and patterns when I began quilting. But quilting--with its preciseness--is, I've learned, very different. I tend to teach myself things, with the help of those who have been there before me. So, when I began my first quilt a couple of years ago, a simple 9 patch of my own design, from 100% Cranston cotton bought at Wal-Mart, I printed out a few instructions on line, and went to work. I sewed a 1/4" seam on all the pieces, sewed in sashing and borders as suggested by my online sources, used the backing as binding, and the quilt--a throw size--came out fine. I even handquilted it because I wanted to learn how and wanted the experience.
Now, two years later, I'm reading and learning more about quilting and the whole thing has become more complicated--and I have to say--less enjoyable. I agree with whoever wrote that if you use the same 1/4" seam consistently and are not using a bought pattern (I've never used a pattern but have made quilts I see in photos or online; I figure out the blocks by looking at the finished quilt) then whatever seam allowance you use should work. Although, as others have pointed out, different fabrics and/or thread do create differences--I'm currently working on a star quilt in which I have lighter and heavier weight fabrics and I see how differently they sew and press--but I'm making slight adjustments for that as I go.
This whole discussion on the dreaded scant 1/4 inch makes me anxious. I keep remembering how happily ignorant I was when I first began quiltmaking. And how well that worked for me!