Kids are wasteful unless they get trained not to be, I think. It sounds like just talking to your daughter isn't going to do the trick. Here's what I would do:
1)For food- you portion it out. If she asks for a snack, give her a very small amount in a little cup or plate. If she complains tell her " You are wasting food that we cannot afford to just throw out.Since you are not being mature enough to only take what you can eat, I will give you portions. You can come back and ask for more when you finish what I gave you." She won't like it- but stick to it. Hopefully after a while it will become habit or she will just be embarrassed about having you hand all her food to her and do better.
2)For things like the water or leaving the lights on. Sit down with her and show her the water bill and the electric bill. If she gets an allowance, tell her you are going to start taking 50 cents off each time you catch her leaving something on! If she doesn't get an allowance, make the consequence something else. If she leaves the lights on- that's 10 minutes less of tv or game time. If she leaves the water running- that's another 10 minutes cut off from her fun time. Dumping out the shampoo? Make her buy her own out of her own money - or take away tv for the whole night. The consequence needs to be something immediate so she makes the connection and remembers.
3)For taking flyers and things like that- just STOP her. When she goes to take a baseball schedule, stop in the middle of the street or whatever. Say to her " I want you to read me what you just took. Is this really something you need or are interested in or is it just something you are going to waste by throwing away?" Make her take it BACK to the person handing it out and give it back to them.
If she throws a fit or talks back or acts up- take away tv time or some other,immediate treat. Tell her that she is too old to throw a tantrum like a toddler and it is just not acceptable behavior, period. If she wants to do fun, big kid things, she needs to act like a big kid.
This is a pain- but it will get the lesson through.
I know it seems like these things are 'mean' or 'strict' but you are teaching a really valuable lesson that will stay with her for her entire life.
on the flip side- always REWARD good behavior. If she turns out a light or off the faucet- praise her! Say " Wow, I'm so glad you're remembering to turn that off! You're helping save energy and helping us save money for other things." Make it clear that the less money goes to the electric bill, the more money you might have to go to the movies, etc. She is old enough to understand how the family budget works. Give her a goal or reward to work towards and keep track of her positive choices- this combination approach can work wonders, IME!
Sometimes teaching our kids seems like just a lot of work for US, lol. But in the end, your child will be better for it and you and she will understand each other better. Good luck!