On last year's Leland Awards cake, I had trouble keeping the letters at a consistent size: they kept getting noticeably smaller as I went from left to right. (There are pictures in my "baked goods" set on Flickr; see the link in my signature.)
Can anybody suggest a way to keep the size consistent across a line? Maybe something analogous to penciling in cap-height, x-height, base, and descender lines, and possibly the letters themselves, for hand-lettering in ink or paint on something non-edible?
Maybe scratch guides into the frosting before piping?
I'm not one to reinvent the wheels, and surely this wheel has already been invented.