what are some simple ways a teacher could evaluate and improve there classroom environment?

The methods really depend on the grade level and the nature of the students' themselves. When I taught in the secondary school level I had the students develop some classroom rules. One criterion was that the rules had to come within the school and board policies. After the students came up with the rules I had the class assess them for doability, practicality, and reasonableness. Once the rules were decided I gave each student a copy.
Another method I used and again, it depends on the class since each class is different was to allow the students 10 minutes time to natter to each other at the end of the period. The condition was that the classwork including the lesson had to be completed, and that during the actual lesson the students had to pay attention and behave like ladies and gentlemen.
Another method that worked for me was to take the class outside to their work. Again the condition was that the students were to do their class work and not spend their time talking about the latest TV programme, film, or other non-school topics.
One technique that is both practical and doable is to let the students have some input into their learning. One year, when I taught English we had to study a novel which both myself and the class hated- in fact we called it "The Broccoli Book" The solution I came up with was to stop teaching the novel at that point and go on to study the play. The proviso was that we come back and finish "The Broccoli Book". We did go back and finish the novel and the students appreciated the break from it.
The thing to keep in mind is that what works for one teacher may not work for another teacher. Another thing to keep in mind is that what works for one class doesn't necessarily work for another.

I am a teacher and I let the students have an input on the classroom environment. Of course this depends on the level of maturity and age of the children. It helps because in my classroom we have specific area that are "quiet zones". From the first day of school the students learn to respect this because many of us can't learn in a chaotic environment. The room should be clean, organized but not sterile and fun to walk into. I have posted the two rules that my students must abide by: #1.We are respectful; #2. We are safe.
I let them know they can break any other rule. I've taught for over 20 years and trust me, those simple 2 rules cover it all.
Good luck in setting up the classroom.

Some of my teachers handed out a evaluation sheet.