Well, this instructable goes over how you can make the rings, my results with them over a 6 month range, and just ways to conserve your material for best use, and an alternative way to make them and have them finished off as for aesthetics.
You will need:
2" x 12' foot lashing straps (Harbor Freight Tools: $3.99)
2 rolls of 244 lb capacity nylon rope (Harbor Freight Tools: $1.49)
2x 1.25" x 60" pvc pipe (Lowes: $1.50 each)
Aluminum foil and a large cookie sheet
an old fish pail
Gorilla Glue Tape
Step 1: Cutting the PVC to Size and Prepping It
Take one 5ft section and cut it into three equal pieces of 20 inches each - trust me, that's all you'll really need, and in this way, you'll be able to make two more pairs of rings for friends and family. Once the pipe is cut to size, and you have two equal sections, tape off an end on each of them using some duct tape (gorilla glue tape has bad results in an oven). Also, wipe down the outside in case there's any dirt or residue stuck on the pipe sections. Tape one square piece over the tip so that it comes down around the sides a bit, then one section all the way around the brim of the pipe's end piece.
Step 2: Pour in the Sand
Place a funnel in one end and start pouring play sand in. This is done so as to prevent the pipe from kinking when you go to bend it. Tap the bottom on the ground so that the sand settles further down. Right when the snad is within a few millimeters of the top part of the pipe, tape it off again, same wasy as you did for the bottom.
Step 3: Cooking the Pipe
Preheat the oven to 375 degrees F., and once it's all set, place the pipe section on a cookie sheet with aluminum foil on top of it. I let mine cook for 15 minutes even. Using some oven mitts, squeeze the pipe down into the bottom of an old fish pail. Let it sit for 10 minutes before removing it. No just due to heat on the latter, but due to if you take it out, it will move and be out of form when it hardens.
Step 4: Cleaning and Cutting the Pipe Sections
Now then, cut open the duct tape and pour the sand out, either back in the bag to reuse, or outside somewhere. Then use the hacksaw again to even up the ends of the pipe sections.
Step 5: Tying the Knot, Finishing Up
Now comes the cool knot part. It's called a snake roll knot, learned it back in Scouts. It's meant to constrict the rope as it's pulled on, like a snake.
Start by threading the rope through the pipe sections, until it goes through at least three times. Then get two equal sections, one in each hand, put your foot on the ring, and pull those rope sections until all of it is super tight.
Now for the snake roll knot. You have two ends that should come out facing each other: one should go one way, and should go the opposite way (if one side is on the left, the other piece of rope should be on the right). they both coil around the rope three or four times, depending on how much space is available. Then you tie a square knot in the middle, left over right, then right over left. Pull it tight, then stick the extra ends of rope in the ends of the pipe sectionals.
After the knot is tied, take some gorilla strength glue tape and cover the rope section, so that it doesn't come undone. Now put the lashing straps through it, like in the cover picture on the instructable, and start doing simple workouts like pushups and dips. Gymnasticbodies.com is a great website for rings exercises.
That's all, and I'd like to thank catmanducmu and his instructable, https://www.instructables.com/id/How-to-make-PVC-gymnastic-fitness-rings/, for inspiring me to make my own changes. On that note, the only p[roblem I've experienced is that after 6 months, the lashing straps metal piece tends to break, so you ultimately have to tie it together in a general square knot, and that should hold just fine.]