That depends on what your requirements are going to be. For example, our family did this last year with the requirements that we do at least 3 attractions and eat something in each park. If you are just going to go to each park, do whatever you feel like (some parks 1 rides, others 4, etc.), that will change up the strategy.
Personally, I would not start at Epcot. Animal Kingdom has morning EMH, so I would have started there. That way, I could do stuff there and get to another park not long after it opens. Since you are doing Epcot first, I'd go ahead and go to DHS from there. What I'd do, though, is either take a bus or I'd boat to Boardwalk (first stop) and then walk to DHS. You'd get there faster than just taking the boat and time needs to be on your side. This is where I would use my fast passes. From there, I'd head to Animal Kingdom since things are usually calming down there later in the afternoon and it's rumored that The Jungle Book show/Rivers of Light may not still be going on at that time. Then, I'd do Magic Kingdom last. It has a ton to do so you'd likely be able to do some fun stuff as well as use a fourth fast pass here that you could have started searching for on your phone as soon as you used your third one at DHS.