Start with pressed fabric and a pattern. A side note here: since you will be working with the bias cut of the fabric on many of these seams, be sure that you press your fabric rather than ironing. Ironing encourages distortion. Also, if you aren’t paper piecing make sure that your templates are very accurate. Small changes in angle result in large changes in the finished block.
Build the individual blocks. (Shown below are three blocks face up, one face down.) Sew the seams to 1/4″ from the edge of the fabric/pattern.
Sew the blocks pairwise in the desired configuration. Remember to start and stop sewing 1/4″ from the edge as shown.
Press pairwise seam so that when the pairs are lined up the seams face opposite directions. Sew the last seam.
Open out the block face down.
Then open out all seams and finger press the seams in a clockwise or counterclockwise configuration. that is, press the seams so that each seam goes towards the same quadrant of the block.
Notice that this gives you a tiny little mini pinwheel in the center. Below is a closeup. I could have chosen better fabrics i suppose.
Remove the paper if you’ve paper pieced. PRESS don’t IRON the block.
The only lumpy spots should be where the seams at the edge are.