The reason for the seam being pressed open is to reduce the bulk in the seam. Especially at the hem. What you do depends a lot on the weight of the fabric you're working with. If you're ok with the bulk issue, then it doesn't really matter which way you press the seam. You might want to follow the seam up to the crotch area and see if the seam is still open. If it goes one way or the other, then do the same thing.

That makes sense, thanks. The fabric is fairly light weight so the bulk isn't really an issue.

if you are Making pants,,, you can press heavy seams open or lighter to the back.

IF altering... PRESS THEM THE SAME AS BEFORE. IF THEY ARE PRESSED TO THE BACK AT THE TOP... CONTINUE THE SAME WAY.