We will be visiting USO/IOA on a Thursday and would love a game plan to get us through both parks in one day. My son is only 47 inches to date and hoping he gets to be 48 by this trip so we can experience WWOHP, etc. We plan to be there from opening to closing (9-9).If anyone out there can help us out we would really appreciate it!
With that said, my advice is:
Arrive at Universal city walk 30-45 minutes early. It will take about 10 minutes, depending on your group, to walk to the parks. You will want to be at the gates of IOA at least 20 minutes early. Once the gates open head straight to WWOHP and get in line for Olivander's. After Olivander's head straight to FJ. Then you can head to the roller coasters, butterbeer stands, or shops. Owls Post will get very busy very quick because of how small it is. Honey Dukes and Zonkos are also pretty crowded. Number one rule, do not leave Harry Potter until you have done everything, and I mean everything you want to do. You can arrange for merchandise pick up or purchase a family locker at the front of the park for all of your belongings that you buy or change of clothes.
After Harry Potter it will be about time or nearly time for lunch. You can either eat at IOA or head to US and eat. After lunch I would advise heading to US and working your way from Rock-it around to Horror Make-Up show. The park closes at 5 and IOA closes at 7 just remember that.
USF shouldn't take you too long to do. Rock-It, Mummy, and MIB will be your main lines. Around 3 I would advise heading back to IOA so that you have atleast 5 hours to complete the park. Start off in Seuss Landing and work your way around towards Marvel. With the addition of HP most of the other parts of the parks have minimal crowds. The water rides here will get your soaked hence my mention of clothes earlier. Once your get to Jurrasic Park head to WWOHP and see if lines have shrunk any. It should be close to closing by then and most lines should be diminishing.
Don't forget you can always add on Express Passes once you arrive at the park. Currently prices are the lowest price possible for Express Passes which means they expect low crowds.
If at all possible pick a day that doesnt have a Halloween Horror Night scheduled just to ease up on the lines that bit more.
My plan for the 2 Uni parks in a day (late Aug/early Sept)is pretty much the same as Terri's advice - get there early, head to Potter first and get outta there to the Studios. (or choose a day with a $25.99 express pass)
Terri can you advise me too please - if I am not a Potter fan but really want to get on the ride - am I going to be confused with the storyline? I know the basics...Hermione/Ron/he who must not be named etc...
The story is, (SPOILERS)
That Hogwarts has allowed Muggles to come into the castle along the way Harry, Hermione, and Ron sneek you out to go to the Quidditch match and along the way you find lots of... stuff. Just keep your eyes open or else you'll miss what lies beyond each turn.
If this doesn't seem right for your needs, Universal and Islands aren't that hard to get done in one day, just try to avoid riding rides like potter at the worst times of the day (e.g. 10-12).
Walt Disney World's Magic Kingdom
Disney's Animal Kingdom
Disney's Hollywood Studios
Disney California Adventure
Universal's Islands of Adventure
Universal Studios Florida
Universal Studios Hollywood