Your basketweave is fine. As Yin Tx pointed out, your border is a bit off. I usually cut and bevel the outline, it gives you a 'ledge' to place the heel of the tool against. As for the spacing of the impressions, I stamp out 8-10 on scrap to get an idea of how many impressions in a set distance. then you can space them as needed. It just takes practice. Or you can start at the center point and work to the ends. Then if you have a bit of space, you can put something else in the corner, like a large seeder.