home made?
Why?
You can buy lead filled leather wraps for, like $25, each.
Any materials you can buy will cost money, and time, and end up looking lame.
There are guys who love to brag about how they went to the hardware store and bought cheap nickel plated steel rings for less than a buck each... but these are solid rings that you have to literally POP your testicles thru, and what with the potential edema buildup when you are wearing a stack of them, you might easily fid yourself in a situation where you desperately need to get them off and can't.
And then what do you do? call the firemen?
Go to the emergency room?
Its your TESTICLES fellas... you only get two (usually)
Skip the pizza one week and splurge on some properly made and hot looking hardware that will last you a decade or more...
Its money well spent.
My woman LOVES the look of the 3 lead filled leather wraps I wear when we are having sex... and I can wear them under loose fitting jeans without anyone being the wiser.
Some home tinkered contraption just sounds like the ultra cheap married to the ultra ugly.
Do not stretch with ANYTHING you can't readily and rapidly get off if your nuts swell up and turn blue.