I have used several 1/4 inch feet and still my blocks were too small.
I now adjust for scant 1/4 inch and my blocks are now the right size. So it is just a matter of experimenting till it comes out right.
Quilting from the Heartland irons all her seams open. All the others iron to the side. So it is just a matter of choice. If I am doing my own pattern I iron open cause it is easier but I follow the directions in a pattern otherwise.