Here's three pictures from my first ever frame bag. Bad finishing (interfacing is still visible) but the bag still works and is in use today. Duck cloth on the outside makes it pretty much waterproof (enough.) I've ridden it in pouring rain and it was still dry inside. The bag screws to both bottle mounts using a piece of aluminum on the inside, that's why there's no straps near the crank or on the seat tube.



Lined it with wool because.... it's what I had.



Zipper side.



Also... anyone know how to join zippers at right angles? (With both the zipper pulls meeting at the corner in the "closed" position?) I didn't know how so it's kinda a mess at the corner... I sorta just threw a bunch of epoxy on it to prevent the zippers from coming off and forgot about it...

EDIT: For the record, if you want to create a full frame bag like I did. Take quite a bit off from the measurements of your frame. I made the bag to fit EXACTLY in the frame, then I took a half inch off all the way around and an inch off in the front and it was still almost too big for the frame. I think I went for 2 inches wide.