Well off course like everyone else I didn't create everything of my hack from scratch.
Most...Err lets say 90% of it is made by someone else and assembled by me.
When you do a hack you just have to know of what your capable of to do, and if you can do it with the stuff that are on your hands.
For me tbh it wasnt that easy, I've been hacking actively for 3 years, at the beginning I sucked alot, it changed with the experience though.
Also I've made some of the tiels of course, but its not that hard really, you just have to have some fantasy and ideas.
I hope this helped, if not feel free to ask more :>