We went for our first time Dec. 3-13, these are some of the best tips as they were very successful on our trip----it helped us out greatly and we had a fantastic holiday with Mickey!
1. If you have children a great idea is to take or buy a large Rubbermaid type container and fill it with a variety of snacks to keep in the room-granola bars, fruit cups, cookies, cheese and crackers,puddings-whatever they fancy! Then we bought little "fanny packs" at Wal-Mart(one with Nemo the other Barbie) for our two youngest ones to wear. Each morning they woke up and would pick out a bunch of snacks for the day and store them in their fanny pack. They loved this, as they had control over when and what they could eat--we loved it because it saved us loads of money(we carried a shoulder pack and filled it up for the adults of the group)!
2. Make sure if you are travelling with 3 or more people in a room to buy an over-the-door shoe bag. This was an absolute lifesaver! We hung it over the bathroom door and then put all of our toiletries in the pouches. Each person had their own for toothbrushes but the rest was filled with shaving supplies, shampoo, hair products, shampoo, hair brushes, vitamins, etc. This was the best tip I ever received!! It definately helps to keep the vanity area clean and stops items from "wandering off" to elsewhere in the room!
3. Don't think you are going to see and do everything the first time! We tried the first 2 days and realized it was ruining our holiday as we were rushing everywhere---definately make a list of the things you must do(this is where a book such as "The Unofficial Guide to WDW" or Birnbaum's travel books help out alot as you can read up on rides and shows ahead of time and talk it over with the kids. They get so excited plus you know what you really want to do)--do these first. Anything after this is a bonus! It took 2 exhausting days to realize we needed to relax and just enjoy--we know we didn't see it all but it wasn't as stressful on everybody! It was our first time and our kids were big for rides so we didn't get to see the shows but we will the next time-gives us an excuse to go back!
4. Buy disposable rain coats(you know the cheap camping ones that cost only a couple of dollars and fold up to the size of your pant pocket)--they are small and compact to carry and are there when you need them! At Animal Kingdom we felt ridiculous as we were one group out of hundreds who wore our rain coats on the Kali River Rapids. Everyone around us looked at us as if we came from another planet--the others in the raft with us did not have rain gear and kind of laughed at us in our "rain gear" but their two little girls got absolutely drenched. After the ride the parents were literally ringing out their clothes and dumping water out of their shoes--I felt so bad for them! As we were about to throw our rain gear away-a family in line saw the wet little girls and "dry" us and asked if they could have the coats--we gladly gave them to them!
5. I also read tavel books like the Unofficial Guide to WDW and others--very useful but I think the best advice is to keep reading these boards--very surprising how many extremely useful tips you will find!