How I Sew Using Sinew.

 A buckskin thong for sewing looks better, feels softer, is easer than sinew to make, sew, and can easily be tightened when it gets loose, but sometimes I opt for sinew. Sinew too has its advantages: it won’t get loose or stretch, and is far stronger and thus more efficient for tight seams.

Above is an emergency "needle" or needle for a thick sinew thread. Its good to have a few traditional needles with big holes (like a glovers needle) for sewing with sinew too.
Thin needles are best for thin hides like coyote furs.

Wet sinew and use a rigid, U shaped iron (or copper, skomething thin) cord bit to slide the end of the sinew through a hole, which is first made with a thin awl.

Consider an overlap seam with a tight running stitch first. When the seam streaches this seam seems to cover gaping holes that may appear and usualy show up at the stitch of a hard used and streched article with a whip stich. Thin hides will also make gaping holes regardless if hard used.

On the other hand, sometimes you may also want to use a whip stich ... Not sure at this point.

 

A tip to sewing buckskin is soaking the item (especially glove sized articles) in water when finished and wear it dry while stretching it to form. 

When sewing a wet brained skin that is just wrung and ready to hand dry, use sinew for small holes but stretch the hole first. Use a thong from the skin for big holes and major gashes. I dont bother with micro holes.