I want to construct my own capacitor, primarily as an experiment in different plate configurations and orientations, so I can better understand field theory. (In other words, I'm playing, and not looking for an off-the-shelf solution. The building of it is half the point.) I've built small PCB units on the order of a few nanofarads. I'd like to build something larger, on the order of 5-10 uF, which seems to make PCBs impractical. I also want the cap to be unpolarized, so I can run AC across it.
I'm thinking I need a couple rolls of foil, a roll of some insulator, and some way to attach conductors to the foil. But before I just go to Wal-Mart and buy all their aluminum foil, I wanted to ask: what might I be missing? Are there standard techniques for hand-building capacitors? Are there particular materials I should use (or avoid)?