I have cameras that take SD cards and settled on two tracks for SD cards. First are the daily shitkickers which I use for random photos. These cards are either

I have cameras that take SD cards and settled on two tracks for SD cards. First are the daily shitkickers which I use for random photos. These cards are either in the camera or in one of the SD card readers. They cycle out every other time, once or twice a month. The second track are "project cards" that are used for one single project and then set aside once the files are pulled off the card. I don't shoot video, and these are used with relatively slow Pentax 645Zs, so I can get away with using the lower-rated cards as the camera is going to take about 7 seconds to write a single shot to the flash no matter the speed of the card. I buy 32GB cards in bulk.