Say you directly disregard my best advice and show up at the Studios at 11am in the morning because you wanted to sleep in (or maybe your kids wanted to) and take it easy. Even though you've ignored my advice to be at the Studios for opening, you still want to "do it all" so now you ask how to do that? While possible, it's going to be an extremely up hill battle for you to get it all done and let's take a look at how you should approach things.
The reason why I always implore everyone to arrive at the Studios for opening is because when the park gates open up, there is a level playing field for everyone. At that point, every single attraction has no wait and for the next hour, waits will be minimal. By arriving at 11am, you've lost 2 (or 3, depending if it's an Extra Magic Hour Morning day) hours of the least crowded time in the parks. This puts you, as they say, right behind the eight ball. Your first task is to evaluate what you want to do. If you want to experience every single attraction, then you'll need to act fast, be swift, and be prepared for a lot of walking and back tracking. If you're looking for a taste of the Studios for the day, then things may be a bit easier.
Assuming you want to do it all, first thing you should do is very swiftly walk to Toy Story Midway Mania and along the way pray, because you will need divine intervention, as you will look to get a FASTPASS. By 11am, the wait for Toy Story Midway Mania can exceed an hour and your best bet is to FASTPASS. If there is a FASTPASS, get it and return later. If they are gone, look at the wait time. If the wait is less than an hour, get on the standby line. If not, you will need to return during a better time of the day, such as during the Block Party Bash parade at 3pm which siphons the kids (and their parents) away or near park closing. This one step will be exceedingly difficult during the busier times of the year and this attraction alone is reason enough to show up for park opening.
Let's assume you've FASTPASS'd Toy Story Midway Mania (or at least decided to ride later), then you will need to head over to Sunset Boulevard and ride Tower of Terror and Rock 'n Roller Coaster. Go with whatever has the longer standby line first then the other. More than likely you will be riding Rock 'n Roller Coaster first and then Tower of Terror. In fact, if they are both the same wait, go with Coaster and then return to Tower as Tower tends to be the faster of the two.
The important thing to be doing all through the day is remain cognisant of show times. Since show schedules vary from week to week, we can't plan on paper here which show to see when. You will have to be vigilant with show times and as you emerge out of attractions, look at your watch and consult the times guide and if a show is going to start soon, go see that show because rides will always be running but shows are limited.
At this point, you'll want to start working in the other attractions that have less of a wait generally. These include the Great Movie Ride, Star Tours, the Indiana Jones Epic Stunt Spectacular and Muppetvision 3D. Remember to keep show times in mind and sprinkle in the other attractions that should not present any difficulty in getting into with a short wait such as Journey into Narnia, Walt Disney: One Man's Dream or Sounds Dangerous. If you can, put off lunch until late (like 2pm late) so you can take advantage of slightly lower crowds park wide who are busy eating lunch. Go with the same plan for dinner and eat dinner after 7pm for optimal touring conditions. By now you may be seeing why missing out on those first two premium hours of the park was as big of a deal as it is now.
Of course, most guests aren't looking to see every single attraction and are okay with getting a taste of what's in the Studios and returning at another point (even on another trip) to finish up. Moreover, guests aren't interested in every single attraction and frankly don't want to see a particular attraction regardless of wait time, so this late morning task is easier. The time of year will also come into play and those traveling during the slower times of the year will find arriving late a much easier task than those traveling during major US holidays. Keep in mind that if you are one of the lucky ones to be visiting during a slow time of the year that park hours are going to be lot less so it's a double edged sword. While I would highly recommend arriving at the Studios for park opening, if you cannot, all hope is not lost.