I prefer sewing tops together in blocks, instead of rows, I feel like I can keep things straighter/more lined up and for some reason it seems to go faster for me (a mental illusion, I know, but...). It all comes out the same in the end, so whatever works for you!
Not sure about seam pressing, it may matter much in that layout, since there aren't a lot of points coming together. will look forward to hearing what others say though.