I've scoured the internet for the answer to this question for months but nobody seems to have discussed it.

I've drawn a few things but I don't know (for certain) how large everything should be. I know I can scale it but it'll be an issue if the proportions are off. What size do you guys follow (for any of these) as a rule of thumb?

Do you just fill up an A4 page (the size of a legal pad, I think, if you're American) or do you use something smaller? How much of this should be the gutter?

Sorry for all these questions! This has been on my mind for a while