increasing on a garter stitch shawl

Hi, I am knitting a garter stitch shawl. I have been doing a YO increase on the second stitch at the beginning of every row. The shawl is about 10" high right now. I was wondering if I should start increasing at the beginning AND end to make it longer at this point in the construction. Will this look weird? If this is OK to do, what kind of increase should I use at the end of the row? I am afraid I will run out of yarn before I can get it long enough if I don’t start this increase on both ends. Thanks.

welcome to KnittingHelp!
You could do that and perhaps use a M1 or a Knit Right Loop (KRL) and Knit Left Loop (KLL) for the increase. Test these increases out on a small swatch with scrap yarn to see which you prefer ad where to place the increases relative to the yarn overs.
It’ll change the shape of the shawl a bit and it’ll give you longer rows which will of course use more yarn. If you want to get to a certain width sooner, however, it’ll work.