>>40879972
Same way inventors create inventions: Find a need and fill it.
Or do you mean methods of actually doing the magic? Because that is a whole thing depending on how you do magic. Largely comes down to finding something that symbolizes what you want done, and doing something to activate it, as a kind of ritual.
It doesn't need to be a full ceremonial-style ritual, just something that is meant to trigger the event. If you want it to be fucking poetry or lighting a candle, by all means go for it. It's your spell.
The point is linking the two events together. Like a sports fan wearing their lucky socks on game day, you have to tie the two things together and know 100% there is a significance between the act and the intended outcome.
Hope this helped.