Good on you! You picked up the tools and did it. Looks like a good credible first effort. I suspect the "before" pictures would have been a little scary if you took off a whole centimeter. Not perfect but a really good first effort.
First time is the hardest. You'll think about it, how it went, what you see on the bottom of the feet, how the feet look now, what it sounded like when you used the rasp, what the foot felt like, the frog, sole depth, and that is good. You will wonder what you could have done better and that will take you to sources like DVD's, more knowledge, and you'll get better and better.
Something to think about. If you go to an Orthodontist, he doesn't grab your teeth with a tool and twist them into alignment (OUCH!). Instead, he applies constant pressure in the right direction and lets the teeth align themselves. It's pretty much the same with horses feet.
You manage your trims to encourage the foot to grow into it's natural healthy shape. That can take time, it took me over a year, but with patience most horses feet will follow the "pressure" (or lack of it in the case of hoof wall seperation) and correct any issues, like quarter flare, etc.
The key, then, is to know both what you are looking for and how to read the existing condition of the feet to see what direction they need to go and from that what to do to take them there. That's where things like DVD's from folks who know what they are doing (Pete Ramey for example) come into the picture.