it really depends on the fabric- when i look at fabrics i usually 'see it' as either a great backing- or great for a blender- or a great focal print---so- depending on where it falls in my 'mind's eye' determines how much of it i will buy-
i seldom (bother) with fq's unless it's something i absolutely have to have a piece of-but really do not think i will have much use for- or that's all they have-
i was told once to always buy as much as you can afford
if it's a great backing fabric i will buy between 6 yards & the whole bolt
if its a blender i will buy 2-3 yards-
if it's a focal fabric i decide if i would want to use it for more than 1 or 2 quilts- usually about 2 yards-
i rarely buy less than 2 yards- unless it's something that i do need for a particular project and know i only need 1 yard- maybe if its just for a binding and i don' t see alot of future need for it-
i like to cut borders lengthwise often so 3 yards generally will give me the length i need for any border-
but if you make small items 1 yard pieces may be plenty for you to build a good stash-
you really need to look at it the way YOU quilt- and choose accordingly- if it is something you might use over and over buy a couple yards- if its a once or twice then moving on---buy 1/2-1 yard...build your stash to fit your quilting needs- not mine