Hello Hachiman-

I used this pattern for my sporran:

www.serve.com/rbriggs/patterns/pdfs/291sporr.pdf

Here's what it looks like-size large hand for reference



I had to resize the .pdf a little (convert to jpeg via screenshot capture and tweak a little with Paint Shop Pro to get the proportions right), used bison hide for the material. Also changed the strap to a ring attachment style. Not exactly roomy, though. I would resize it 10% larger on the next try and use 4 sets of holes to do the tucks. I would also do the tucks first before stitching it together.

Just a thought.

Ray