get some aluminum and a drill pess a big hole almost all the way through and then a littler one at the end and u got a peg but its kind of hard its simpler to just buy some
That's a pretty detailed and easy way to make pegs haha
But seriously, if you cannot figure out how to make a peg simply by looking at it, and for the hastle it would be to make some yourself, you're way better off getting some QCS pegs.
get a thick washer with a hole just big enough to fit your axle
get some pipe that is as wide as the axle and cut it to the desired peg length (2 inches long is decent)
weld the pipe to the washer
put it on your axle and shred