Like a lot of patterns, Swoon doesn't have any instructions on how to press the seams. If you're an experienced quilter it's not too bad, but if your a bit of a newbie, it can be a bit daunting. These are my tips.
This gives you an idea of how I pressed the seams, starting with the HSTs as described above. I tended to press the seams in the direction they wanted to fall which helps minimise bulk.
The other component is the unit made of of the flying geese and solid rectangle. No matter which way you press the seams, they don't fit with the corner units. So I found it easier to press them open. There is still enough bulk in the seam to allow the seams to butt up against each other fairly well, without being too bulky.