Once you get the 4 patch made and before you do any pressing, go to the back and take out about 2 stitches of the seams that you crossed with the last seam when you joined the two. After those two stitches are removed, lay the 4 patch flat face down and that last seam will almost effortlessly go opposite ways and you will see the cute little checker pattern where the seams meet. If it doesn't go flat, there might be another stitch that needs to be removed. Now press with half of the seam going north and half of the seam going south. I didn't understand this well for awhile either but now that I finally figured it out, I like the finish I get with that extra step.
BTW...I have step three completed except for pressing about half of the blocks. Loved working with another color and can't wait to see what we do with the green.