You can always hold a reflector in one hand and your camera in the other and I have seen many photographers do this.
I often have an assistant hold the reflector, sometimes the fiend of the person I’m photographing. This gives them something to do and keeps them out of my way. If you’re on your own without any help, you can mount the reflector onto a lightstand. Any of these reflectors can be used or attached to a light stand with the extendable Reflector Holder. The Portable Reflector Bracket allows you to mount reflectors onto a light stand. It’s adjustable to hold reflectors ranging in size from 22 to 58-inches. and can be rotated and swiveled for precise positioning.
Joe Farace is the co-author, along with Pulitzer Prize-winning photographer Barry Staver, of a new book called “Better Available Light Digital Photography” published by Focal Press is available at Barnes & Noble and Amazon.com.