Using stash is great - I've done that a couple of years. However, if you are like me, you have no background fabrics. So, don't beat yourself up. Look at your stash and maybe limit your purchases to background and binding.
There's another reason to use your stash. I have a bunch of stash from the mid-90s. Only THIS YEAR did fabric come out that went with those fabrics (for instance red-purple, as opposed to blue purple). I have some fabrics from the 'watercolor' era. Really tough to use with newer fabrics without having to yep, buy more fabric.