I always have 3/4 patterns chosen for my next quilts. I check several sights when they have sales. I pick up fabrics for these quilts. Which ever quilt I pick up enough fabrics for is the quilt I make. Buying on sale, and buying only what I need for a quilt, keeps me from just buying fabrics because I like it. I buy 1/2-1 yard pieces.Depending if its a fabric to piece or a fabric for borders. Or backing fabrics. By having patterns already chosen, I know what I need in fabric.
When I have a lot of leftover fabric from these quilts, then I make a scrappy quilt from my scrap box.