Also, be careful what kind you buy. For example, I have a local Microcenter nearby, so I'm always buying stuff in there. But when I buy their flash drives and set them up as bootable, it seems like the microcenter brand flash drives I've tried so far, on a lot of systems don't like to boot them. Unsure why. Case in point, going to install Windows 10 on a laptop recently, my 16gb Microcenter usb 2.0 drive would make the machine go into a loop when trying to boot. In other words, like the dots when it loads would start, then machine turns off, posts again, same sequence over and over. My PNY 8gb, no problem.
Now if the system was started and I needed to plug in my MC drive to back up or move things around, not a problem at all.