I have found that pressing from the top first has improved the accuracy of my blocks because in pressing from the back first, no matter how careful I tried to be, I always had little pleats in some of the seams. Now I always press from the top first and my accuracy is much improved.
In fact, I am so pleased that this flimsy I just added the borders to was perfectly square and my borders fit exactly. I didn't have to fudge the fit at all.
