If you use PVC pipes for props like staffs or sword bases, or costume structure support, or any other reason, a pvc cutter can really help you with all that cutting. Saws, cable saws, and other powered cutting tools can be used, but I have found the handheld ratcheting cutters pretty efficient for the price and the use I get from them.
The cutter I use cuts up to a 1-5/8 inch pipe which works for most applications I would use it for. There are others that can go up to 3 inches, but they go up significantly in price. I paid a little over $5 for mine, using a coupon. I have seen the larger cutters go up to nearly $50. If you need to cut a larger PVC section, a cable or wire saw can be purchased for about $10, but requires a firm hold on the pipe while you are cutting it. Cutters can be purchased at almost any hardware store, usually near the plumbing section.
The cutter is fairly easy to use, but will take some strength to cut the pipe, especially smaller pipes which tend to be thicker. Just be sure to keep fingers and any important body parts away from the blade area while using it. Ie. keep away from small children. These cutters do come without a ratcheting mechanism. I highly suggest making sure you get one that ratchets, or it will take significantly more effort to make your cut. The ratcheting feature locks the blade at the depth you make it into the pipe instead of springing back out. I should also mention that whenever using tools that safety goggles are also a good idea.
Usually, I have a plan of what lengths I need to cut. I start off by marking my measurements and any lengths I need to cut on the pipe. Sharpie or permanent markers work well for this. To use the ratcheting pvc cutter, unlock the tool and open the handles which will cause the blade to pop out. Place the pipe between the blade and the back of the cutter. Line up your measurement lines with the blade, then begin squeezing your handle. As you cut deeper into the pipe, the ratcheting mechanism will keep the blade at its current depth and allow you to release and squeeze the handle again. Continue squeezing until you have made it through the pipe.
Viola! You've just cut your pvc pipe.
Be aware if you have any long lengths that ends may fall or pop up and smack you if you are cutting on an uneven surface or holding the pipe in the air while cutting. I tend to place the pipe on the floor when I do my cuts. When you are done your cutting, if you are not covering the ends, I suggest taking some sandpaper and smoothing off the ends a bit. They can be a little sharp. Now that you have your cut pieces, you can continue with any other prep and work on the pvc pipe.