Thread color matters this month, especially for white and black backgrounds. If you use a contrasting thread, it is mostly likely to show on the seams where you insert the background bias into the background.
Be sure to cut the bias as true bias on a 45 degree angle (align the 45 line on your rotary ruler with the selvedge edge or cross grain), so that you'll have as much stretch as you need.
Always sew the curved seams with the bias strip on top, so you can easily manipulate it. I slightly stretched the bias on outside curve edge and eased it a little on inside curve.
I stitched all of my blocks WITHOUT pins, concentrating on the inch or two in front of the needle as I sewed.
If you are having problems inserting the bias "reeds," then trim them narrower.
If you are using too-thin fabric, you may have problems pressing the block and will end up with lots of puckering when you use steam . . . ask me how I know ;-)
Press the seams in whichever direction will result in a flat, uncrinkled block. The first thing to try if you are having problems pressing the seam is to try pressing the seam in the other direction.