I usually buy some of each fabric in the collection.
Once I get home with the fabric and depending on how much there
is I will put it all into a zip lock bag (usually a 1 gallon or the 2-1/2 gallon)
it there is a pattern that goes with the fabrics (and I have a copy of it) it
goes into the bag with fabrics also along with a details notes I make with
my ideas, thoughts etc.