I like pressing to one side (usually the darker side). I think it makes for stronger seams. I also like the way seams nestle together where they meet. Unless the quilt police are in your sewing room, do what makes you happy and what works for you.
By the way, are those the "Happy Cows" from California in your avatar? The commercials on TV are very clever and usually catch my attention when they come on. My favorite one is from a while back when the cows would be laughing because their feet were being tickled by an earthquake (not funny I'm sure if you live there)!!!

I don't think it's a big deal if you press your seams open.

One problem I have when pressing seams open is quite often the seams on the underside "flip" when sewing to another piece or block. Anyone have any suggestions as to how to prevent that?

oops

It flips becasue it drags along the edge of the machine as you sew, if you slow a bit and just lift up a bit or even stop an lift, if it is pressed it will flip the right way. You really just need to be aware and keep your eye on them, it is the same if they are pressed to one side, some times they get cuaght going in the wrong direction.

I am in the habit of pressing seams to one side, but when I made the quilt you see as my avatar, I wish I hadn't. most of the sections were either HST's or flying geese. I was chain piecing and pressing, so everything was pressed the same way. When it came to assembling sections (some were turned in different directions), I discovered that I should have pressed some to the opposite side, but I didn't go back and do it again. I grew more and more frustrated with the amount of hard pressing I had to do to keep the blocks nice and flat. (I also warned the longarmer about the bulky intersections. She assured me that she used strong needles, and didn't end up having any problems, thank goodness.)
That lesson learned, I will be pressing at least some of the seams open in my current and future projects. The current project is a hopscotch pattern. Some of the blocks are pinwheels (made of HST's) and the others are 16-patches. I'm definitely going to press the 16-patch seams open so that there are the same number of layers everywhere. I have already pressed the HST seams to one side (habit!); it remains to be seen how well they "nest". If I'm not happy, I'll be doing a lot of re-pressing!

For me, whether I press the seam allowances open or to one side depends entirely on the quilt pattern and how the pieces fit together. On the quilt I am piecing now, there is no good or feasible way to press the seams allowances to one side; the bulk on alternate blocks would be huge with lumps everywhere! I have to press the seams open on this quilt.

On the last one I pieced I had to press all the seams to one side ... there are 120 "melons" done in 6-colors, chevron style ... and then I had to top-stitch quilt around each melon because the seam allowances wanted to "escape" and go in different directions where the 6 color strips are sewn together. I'm sure this doesn't make any sense without visual aids, but trust me when I say those melon seam allowances needed to contained because they couldn't be tamed.

I don't think there are any hard and fast rules for any aspect of piecing and quilting. You have to go with what works best for you.

My background is clothes construction . I press all my seams open , that's the way I learned . They lay so much flatter that way . Seems like they line up so much better , too . But everyone has their own way of doing it :D Annie

yep each project has to be judged on its own :D

Thank you all for answering a tough question for me. I will now press all seams open. I can be more accurate then.