If you like scrappy quilts the best, then you could organize your fabrics by color. Select a pattern, then start pulling fabrics from your color families and cut the strip sizes you need. I completely stopped stashing fabrics for backings and borders. I either wait until I'm finished piecing or cut 10.5" squares from my stash as I cut strips.
I used to buy matching fabrics for a quilt and get paralyzed by the fear that I would run out of fabric. Once I read about the scrap user's system on Bonnie Hunt's quiltville.com website, I found it so freeing. I prefer controlled color scrappy quilts, so this works the best for me. Even though I only have a small stash, I know that I won't ever run out of fabric for a quilt, I can just go shopping for more fabric in my colors and make some more blocks. If I make too many blocks, I can use them later in a backing or border.