So, there are actually several different ways for making sigils. You could do it the chaos magic way by creating a phrase, removing the vowels, and forming a symbol out of the pieces of the letters that are left.
There’s also a method of sigil making where you combine different common sigils that embody the overall meaning you want to convey. For example, the sigil I created for the newsletter a while ago uses this sigil method.
The upside-down triangle with the line draws on the grounding stability of Earth’s energy. The X represents the habit, and the full line through it with the vertical lines represents the path to stability, while the habit can’t get through because it’s blocked!
Then there’s another method of sigil creation using planetary grids. I’ve only done this once using Jupiter’s planetary grid. I learned this method from Ivy the Occultist!