Unfortunately USH does not really have secret things you can look out for to make your trip that much more special. Everything is there in front of you. The Barbasol can is one of the few things that can be overlooked but I assure you that on such attractions, you're not going to be focused on looking for them. You either see it or you don't and if you don't, you won't remember.
Another little neat thing on the Jurrasic Park ride not so secret is something you won't miss if you just look around to see what a great ride you're in. I bet you'll see it.
I suggest you get at the park before it opens. Transformers and Despicable Me have early access half hour before the rest of the park opens. Hit up Despicable Me first as its this year's big attraction.
Do the Studio Tour before 1pm. The Studio Tour is the most popular attraction so in the earlier hours boarding is quicker than the expected wait time. It can sometimes practically be a walk on before 10am.
Transformers in the lower lot can get a lengthy wait time but again, if you do it in the earlier hours, you can be done with the entire lower lot attractions in less than 2 hours. Also, check out the NBC Universal Experience exhibit while you are on the lower lot to look at some great movie props and costumes. And maybe take a photo with Optimus Prime, Bumblebee, or Megatron right across the exhibit.
Adding to what Chris said, if you're going to eat at the Jurassic Cafe which has a pretty decent selection of items, eat on the upper dining area. The ambiance is much nicer than it is down below or inside the restaurant. The stairs are to the left of the doors.
If you must watch Shrek 4D, I recommend you do it within the last hour you'll be at the park. The line for Shrek 4D is always packed during the day. Around the last showings, its usually a walk on.
The Simpsons line can also get incredibly long. There is no time during the day where the line short. At least not anymore...unless, again, its in the early hours. -_-
Watch Waterworld. The best seating area is the middle section so it quickly fills up. Also, I hope you don't have a problem getting wet even if you don't sit in the splash zone!
The park starts to noticeably seem crowded past 2pm. If you are there for a whole day, you should be able to watch all shows and board all rides at your leisure. You don't need an entire day for everything either. I can spend entire days there only because I love being there. haha!