2-up on A4 sized.
I only use standard quality paper most of the time, but if I'm putting them through posher letter boxes, I print on something a bit nicer.
If printing large quantities, it's probably cheaper to have a printing company do it. For the small amount I put out, it's hardly worth it.
I wrote 100-200 a week in my earlier post. On reflection, it's probably rather less. I may even stop doing it when I've used them up because, at that low level, canvassing is less effort. It's handy for winter though because I'm not keen on knocking in the dark - it can spook some people a bit.