Any suggestions on best viewing location and how early to stake out our spots? We'll be there the beginning of Christmas week (Dec 19-21). With two short kids, we want to make sure they can see as much as possible. My only comparison is Disney parades a few years and having to be there crazy early and still not having great success.
Yesterday we sat in front of Max Factor on Hollywood blvd 15 minutes before the parade and barely got the spot. A prior day, we arrived 30 minutes before and that area had plenty of space to choose from, but expect it to be busier on the days you are going. Choose a spot with room on the curb (not in front of trash cans) as you must have your feet off the street. The crosswalk curb cutouts seemed like they were the last area to be filled and were fine for use.
We wanted to sit under the confetti cannons on the left half of the Beverly Wilshire, but that spot was taken 15min before. Thankfully, the light breeze made the Max Factor curb the place where most of the confetti landed and it was awesome. For other areas, you can spot the confetti cannons on the top of the buildings, usually 4 or more tubes poking over the edge. Totally worth it to sit under these.
Starting at Vine, and turning left on Hollywood is the initial route. So that initial section of Hollywood blvd is the start of the parade, so you can be finished first so long as you want to exit the park after or head over to Islands. If you wanted instead after the parade to continue to Diagon Alley or other areas, this place is terrible as you have to fight crowds still watching the parade all the way along plaza of the stars and then to 5th ave. We tried it once and would not recommend. If you want to get to the rest of USF after, look for something on the north end of 5th, west side. Maybe on the pond side of south st.
For a double bonus, there is a designated UOAP zone at Mel's diner where you can see the parade twice if you like, but it was full 40 minutes before the parade, so that might require planning an hour in advance or so.
As far as timing, for us the days when the parade started earlier had more character interaction because it was brighter out. On days when the parade started later, for us the lighting of the floats were nicer, particularly the ground effects lighting that makes them look like they are hovering.
NOTE: If at all possible DO NOT sit next to a family with a cute sub-one-year-old. The performers will not interact with you much, as most of them make a bee-line for that baby. If you are that family with a cute baby, make sure she/he is in plain view and bring a video camera because you will have TONS of awesome performer interaction.