I have twisted seams if needed so they would nestle and make as perfect a seam match as possible...it is better to do that than have that big hunk of fabric all on one side! And no matter how careful I am when I begin a project with ironing one way, then the opposite, there always come a time in the construction when boom! there they are..all facing the same way! So I do like jenny did...no prob......I am a longarmer and my APQS just sails thru those seams....these machines are heavy duty and a little twist doesn't even make it blink! Even if someone sews a seam with all seam allowances to same side...she just digs in and keeps going..........as far as clipping.....I have never done that and wonder if cutting into seam allowance might weaken that area and cause shredding.....???