My husband and I spent NYE at Disneyland and DCA last year. We originally planned to be in Disneyland until midnight, so we showed up at park open and got a locker to store our jackets for later at night. We spent most of the morning doing ride attractions while lines were shorter. Then at lunch time we had a relaxing lunch at Cafe Orleans (with pre made reservations) and then the rest of the afternoon and early evening we did shows like Mickey and the Magical map and Lincoln, and a view of the Christmas parade. Things that we wouldn't have to stand in long lines for or fight crowds to experience. It was really crowded and it was nice to take it easy and the afternoon and relax. We were told the park never reaqched capacity or closed and we were suprised since it seemed so crowded.
At dinner we had reservations at Carnation Cafe, and we saw at least 5 groups of people try to get in but there was no availability. They were not happy about being turned away. . Some time during the day we found out that Disneyland was doing a midnight celebration at 9pm to celebrate the new year with WDW. So we thought perhaps we would do this and then be able to see the DCA midnight fireworks. After dinner it was about 8 pm and people were starting to get spots in the middle of Main STreet for the early celebration so we joined them. Perhaps the early fireworks/NYW celebration isn't a ts spectacular as the actual midnight one, I don't know. But seeing that early celebration at DL was a great decisions. After that early celebration we went over to DCA and it was so nice.
There weren't very many people and we enjoyed the swing band by the Carthay, and were even able to ride Tower of Terror with no wait. A lady we talked to at DL gave us fast passes for the midnight show of World of Color so we waltzed in at the last minute for that and even that wasn't as full as we thought it would be. The midnight celebration at DCA was really awesome I t was so cool seeing both of the parks midnight celebrations even if DL's was early. Once the midnight World of Color got done we went back over to DL to clean out our locker and had no problems getting back in and there was still a festive atmosphere . '
So I guess in short my advice would be:
1. go early and get attractions you really want to do done, grab fast pass for later to some
2. plan to relax in the afternoon and evening in the park
3. get a locker
4. make reservations for dinner and lunch if you are spending the whole day in the park (not worth fighting crowds for tables when one can be reserved for you.)
5. If Disneyland has an early celebration do that then go to DCA.
6. Pack your patience
I was told that NYE would be a nightmare in the parks, but we had a blast. It was one of our best Disney days ever.