Decks can be sooo picky sometimes..
I was making a bag for a deck when another deck simply stepped in and stole it.
Well, it was laying on my desk along with the other one and after nearly finishing the bag, I realised that it would suit the other deck so much better that it got to move in instead..
I mix and match fabrics but do like them to feel "solid" so they don't loose their shape. I've used some synthetic fabrics but do prefer cotton and linen for most of my bags. Silk too, though that comes in rarely due to it not being all that easy to find the real kind of silk around here and I do prefer natural fibres mostly.
Color for me is mainly chosen on a deck-to-deck basis, or a feeling I get when I use the deck. Some are greener and others more blue, yellow or even metallic.
Why not make a one-card-draw for inspiration on making the bag?
The chosen card could give you inspiration for both color, material and style.