Consideration #1 and this is a biggy!
When you are within close contact with other park guests use "inside voices". When in, lets say a monorail or in a bus that is crowded with people, try to whisper. People in the transportation with you do not want to hear your whole conversation. They are on vacation and trying to relax. I was on the monorail and a woman that was sitting behind me was so loud I almost put in ear plugs. Its hard not to get loud when your excited but do as I use to tell my pre-school students use "inside voices". If you're alone in the monorail have fun! I know I usually do! Use this rule on rides too. My niece didn't and was yelling in this poor girls ear in front of us! Luckily for my niece she was very little, and very cute so the girl did not mind as much.
Consideration # 3
STROLLERS!!!! I have a niece, we have a stroller! You will never understand what a pain in the tail it is to have a stroller at Disney until you actually experience it! BUT I spent many many years on the other end of the stroller wars. I am a Floridian, I wear sandals at Disney so when people do not pay attention when pushing a stroller the backs of my legs pay the price. Give the stroller over to a family member that you know will pay attention when pushing. We have guilty people within my family that have almost run over poor guests. That is usually when those of us who are hyperaware take over the driving privileges. If you don't have kids pay attention to those around you with strollers. It is a lot harder for those with them to maneuver through the crowd so be kind to others.
Consideration # 4
Something that everyone should know before approaching a park entrance is to open up all compartments of your bags (including bags inside the bags) when standing in line at the bag check. How many times have you been waiting to get your bag checked and the person in front of you takes forever to open every zipper on their bag when yours is ready to go. I know there should be a first timers guild to being a good tourist at theme parks! oh wait is there? maybe I should write it!! well anyways open your bags and move away from the table to close your bags, we are all in a hurry to get fastpasses to Toy Story Mania or Soarin or Expedition Everest. (O ya and you can walk down both sides of the table for the security to check you bag, you don't have to stay on one side)
If you smoke please go to the smoking area's. Non smokers don't want to smell it and its really bad for us and kids to be breathing that in. When taking photos of family members don't stand too far away. People will always walk in front of your photos which sucks for you and them. Photobombs are fun but I don't want to be looking like a crazy person in your pictures! I wonder how many photos I am in from all my years at Disney, everyone go check your family photos for me! BEWARE when taking self portraits others might think you are taking a picture of things across from you and stop for you to take a picture. This happened to me and my mom this past weekend when taking a picture on the bridge at Animal Kingdom. I felt so bad for the people, but it was really really funny.
So in conclusion remember its your vacation have fun but please be aware that there are people around you trying to enjoy their magical vacation as well. When you're not using good theme park manners it could make their experience a little less magical. I have also had others enhance my magical vacation experience. I love talking to new people or helping someone out that seems lost or needs a picture taken. Of course cast members are the best at making a vacation even more magical!
Is there anything I forgot? Is there anything that bugs you when your at Disney that could be easily taken care of with a "what not to do at Disney parks book"?