Both. I buy and tie more than I need, but when I fish I aim to be light and mobile. I started the season with 1 fly box in my fanny pack. I've added 2 more that I probably don't need, but they don't weigh much, so.... Sometimes I leave the fanny pack in the car, and just tuck one fly box in my pants pocket. I have 3 fly rods in my car right now. I might pick a different one each time I'm out...but I will only have ONE in my hand when I leave the car and head for the water.