I check the remnant bins first for bits of this and that. Amazing how often you find the "perfect" piece in there. Then when at least 50% off, I may buy the whole bolt if it is for a quilt I am working on. I also get the bolt of basics like beige, white, black, etc, that you can always be used for something.
I also tend to have "periods." I have gone through my fleece period, quilted double sided period and am now entering my quilting period. About to finish my first quilted wall hanging and working on first king size quilt.