When you are reassembling your cut and moved pieces, do you use a full 1/4" or a scant 1/4" seam?

When you sew your cut pieces back together, do you go horizontally or vertically?

Does vertically give you a crisper block as opposed to rejoining the pieces horizontally?

I'm wondering because I've done 2 completed blocks for my queen size quilt, horizontally doesn't seem to be giving me the cleanest finished block. (Not that I think you would notice once the top is finished...but still.

Thanks!