I was never fond of the beginning chains for crochet in the normal way it is taught. When you go through the top stitch for the first row it left an unfinished edge that was almost always tighter than the final edge of whatever project I was working on. It may have been the way I did it, but it always seemed to be the case.
Then they came out with the sc and dc foundation chains. It allowed the edge to be more flexible, but regardless of how many times I read the instructions and watched videos I still don't think I ended up doing it correctly.
Somewhere along the line I began to work in the beginning chain in the bottom of the stitch rather than in the top of the stitch. I simply flipped the chain over, and worked in the single "bump" all the way across.
Here you can see the single stitch "bump" which is on the back, and when you work into that it leaves the full stitch you normally work in on the bottom. Now both edges of the project will look the same and will have about the same elasticity rather than the beginning chain being tighter.