Basically you just need hole for the straps and the wooden dowel in the bag to keep it's shape. Might not be that great though. Or you could get a Bagman with the qr bracket, so it would be stable and you'd only need the holes for the zip ties.
I just realised I’ve got a load of quite wide metal eyelets that would be good for the loop holes. Cheers for that link - good to see a similar thing to what I’m thinking.
Basically you just need hole for the straps and the wooden dowel in the bag to keep it's shape. Might not be that great though. Or you could get a Bagman with the qr bracket, so it would be stable and you'd only need the holes for the zip ties.
And here's a guide for a handlebar bag, http://www.bikepacking.com/gear/camera-handlebar-bag-diy/