This can be called as a follow-up question of Most significant reasons that led us to (La)TeX
There are many ways to draw graphics pictures in TeX, LaTeX and Friends. We can draw it using external programs, or use some graphics tools (TikZ, PSTricks, Asymptote,
picture environment), etc.
So, which graphics tool(s) / external program(s) do you use? Why did you choose it(them) but not any others?
A story showing how you came to the tool is very welcome!