Haha, I made one a few years back for Chris and Léo. (Someone needs to bring these guyses back to Milandes, I miss them.
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Don't forget to follow the "sens du fil" of the fabric when you make it, because otherwise you'll get rained on. And have lots of spare needles on hand. I guaranty you'll break more than one. Depending on your canvas, you should get the heavy duty needles 100/16 ballpoint or 90/14 leather. Thread isn't a big concern, all purpose works well as long as you don't get the cheap stuff. The big rolls for sergers work. But they will probably piss you off because they aren't as sturdy as the "normal" spools.
The French seams work the best for sturdiness so you need to remember to put about 1 inch to 2 inches of extra fabric around the edges to give you some breathing room. That depends on how comfortable your are with your machine. Most of the time, ironing canvas is out of the question and it makes for clumsier seams.