The way I prefer to work is on loose canvas taped to the wall or pinned to a bulletin board. My reasons for this is because it offers a lot of freedom. I can decide later to crop the piece, change its dimensions dramatically or, as will happen, toss it aside forever because I'm just not that interested in presenting it. It gives me the freedom to work without too much pressure and to know resources are being used well.
Because of this, I have to stretch my own canvases, or as I do with smaller oil paintings, mount them in hardboard.
Today I stretched my Meditations of a Lone wolf with heavy duty blick stretcher bars. I took clips of my process throughout with snap chat! (User name kpottermt).
first, I put the bars together, with cross bars to help prevent warping. Then, I muss around with the canvas to find out where it fits best. It's actually quite freeing to bend and play with a painted canvas, though a bit of gentleness is necessary. I place 2 or 3 staples loosely to make sure I have it right, and then begins the stretching.
Canvas pliers cannot be overrated for this process.
Once it is stretched, I put in the keys which help stretch and straighten, then I use either eyelets or d-rings on each side with wire between them for the hangin system. It's a fairly easy process, but requires attention and thus time.
At the end, I am always so thrilled to see the piece hanging on the wall!