I use TikZ in LaTeX, it's awesome, has a comprehensive manual, great examples website http://www.texample.net/tikz/examples/ to learn from. The secret, I've found, is to avoid programming in TikZ as much as possible--it's terribly clunky as a language for anything beyond the basics--by writing macros in LaTeX (with \newcommand) to use in TikZ for any shapes you'll need repeatedly. They can have as many parameters as you like.

If I need control over every pixel I write graphics programs in Python or Cython or C, or use GIMP.