Sometimes the pattern dictates the fabric sometimes it is the other way around. Lately I have had a case of wanting to cut all the componates out for 2-3 quilts putting each set in a project bag and then start putting one together. Only the first once I cut all 224 gingham block & 224 muslin for the hst. I just couldn't leave it until I sewed them together but I managed to stop before cutting them apart. Then moved to cutting the componates of the second quilt (396) rectangles, haven't finished cutting all these yet. Oh, and I like to scan the actual fabrics into a folder & import it into EQ to use in the project so as to see how it will look. I often do this before I cut any thing to see if it works with a particular pattern or block. It helps.