I press seams to one side as often as possible...my one exception is when attaching binding strips, which are attached on angle, not straight across- those I sew open. Btw, I only miter border corners if the print is a design that is linear. Then I want that print running around center as a pic frame. Otherwise, just straight seam binding....if it's a solid or tonal, who sees all that extra work, and an all over print just blends in.....also a bit less fabric is wasted....