Sorry, flubba.
I taught myself to sew from Very Easy Very Vogue patterns, having always bunked off sewing at school. But what I do remember is that, when cutting out, you should make sure that big motifs - huge flowers or whatever - are centrally placed and that they meet neatly at seams. So, for example and as the judge said, the chap who made the boldly-patterned dress should have cut out the back so that the seam ran through the centre of the leaf-shape and when the two pieces were joined together it looked like one leaf.
And if you cut something - it's usually a neckline , a shoulder line or the front edge of a dress bodice - so that the cut goes diagonally across the grain of the fabric [the grain is the length of the fabric], you should then sew along that edge, just inside the seam line and with very small stitches, so that the edge is stabilised and doesn't stretch. Generally, the stretch that you get on the diagonal is a good thing - that's why we saw one of the competitors making bias binding to finish off a hem, as the bias makes it flexible - but you don't want it when it means that part of the garment could be stretched out of shape.