What currently works for me is a homemade rack for larger items and a binder system for the multiple shape templates. My rack is a board, onto which I glued disposable chopsticks at narrow intervals. Just measured, marked, glued, then gently put another board on top while the glue dried. It sits on a counter, next to a book case, so that the larger rulers can lean on the book case. The smaller ones rest at the ready like little soldiers ready for their call to duty.
Mats are everywhere. Different sizes in different places. Most active machines have a cutting mat next to them. The largest one lives on the cutting table. I have a large portfolio style carry bag, c.70's, which had been made for carrying a drafting board to job sites. I covered the board as a pressing board, and keep the big mats in it for on-the-go. There is a pocket on the front for a T-Square, but I dare not put rulers in it for fear they'll get down so far I won't be able to reach then. I do have a couple of large sheets of cardboard inside so I can keep the large rulers on one side of the mats and the board on the other. It has a hand carry strap. I want to put a shoulder strap on it. It's also O.D. Green. Want to attack it with iron-on appliqués or fabric paint . . . in my spare time.