YukonViv gave you excellent advice, I discovered they weren't as bad as I thought when I relaxed, went very slow and methodical and was very accurate. Marking the seams with a very visible dot where you will stop and pivet really helps, don't raise your needle for anything! and I used the end of my seam ripper to make sure the fabric on the underside was in the right position before I resumed sewing. And after my first one the following seemed somewhat easier, I think it was because I was less tense by getting through the first one. Good luck!