are you cutting the angles that touch each other at an angle?
This is why I recommend doing test pieces...it helps a lot during the building process.
your cuts look clean, though. Believe me, my build looked much worse.
I would recommend finishing the boots, and testing all the different techniques you want to see what you like best on the boots.
Then, if you don't like the result, try again with all the new things you've learned. it helps a lot.
On my first build, what I did was experiment on one piece like 3 times until I got a result that I liked, then started on more pieces with my newfound knowledge. worked really well for me.
watch
THIS. it will explain everything you want to know about foam.
Hope this helps!