Seed stitch

[mdkb904]

For the seed stitch do I go under one loop or both loops on the  foundation chain 

[bgs]

This is what I do

https://www.anniescatalog.com/crochet/content.html?content_id=593&type_id=S&scat_id=368

[Granny Square]

Doesn't matter.  Any of the 3 ways to stitch into a chain will work--(1) the above video's method (chain facing, under top loop + back bump); this leaves 1 unused loop as the bottom edge (2) chain facing, top loop only. This is how I learned, it leaves a bottom edge that looks like a 2 strand braid  (3) using the back bum/bar - this leaves the 'chain facing' side as the bottom edge, but pulls the fabric tight.  The first 2 methods don't change the tension, the third pulls the chain tight and is IMO also fiddlier (probably due to the tightness).  If you want to use the last method, use a larger hook for the chain, then back to the 'right' hook for the stitches.

There's a 4th way to begin a row, a foundation stitch.  Some people think it looks better, (I am not one), but it has limitations - will not work with all stitch patterns.  I avoid it unless I encounter an 'indent out' that needs to be at a right angle.