one suggestion:
if you are visiting the NAs make sure where ever you stop do take pictures of people throwing trash as well.. and post them here (or on a separate thread)
actions like that are hard to miss.. i have seen it plenty of times and i am sure Pakwheelers have witnessed it too
difference iss se ata hai ya nahi... but newbies & selfie takers will get aware how they will look if they throw trash somewhere without a slight concerned look on their face