We look at what the park hours are, as it's such a great park and we usually stay from opening to close. If it's Christmas time or Summer, we make sure to go on a day when they have the special Christmas shows and summer shows because those are so good too and the park is usually open for extended hours then. So number 1 is we pick the day we want to go. I've never been to the Seven Seas festival, but we'll be going on a Seven Seas festival day in March.
Number 2 is that we decide what we want to do for food. Do we want to do the special "Dine with Shamu Experience". If so we book both that and our park tickets. The other fancier restaurant that isn't on the meal plan is the Shark Underwater Grill. If not doing either of those, we then ask do we want to do the "Meal Deal" that usually save us money if eating both lunch and dinner in the parks and not doing special dining. Then we go online and buy our tickets because you get some savings for buying tickets in advance. There are often combo deals for tickets and meals too that save some dollars.
Number 3 when we arrive we pick up a show schedule and plan to hit three shows or so, getting there if it's a busy time of year, close to a 1/2 hour ahead of time of the show to get a good seat. Other than that we just love wandering around and doing whatever we want to do (so much less planning and so much more relaxing than Disney or Universal). One other tip if going to the Wild Artic area, go anytime except right after a Shamu show lets out (it's always packed right after a Shamu show, but very manageable at any other time). Coaster lines are shortest at opening and in the evening, but often aren't bad at any time. We usually hit one of those first thing before our first show.
Enjoy. We love SeaWorld and think it's the best theme park in all of Orlando for a multigenerational group to enjoy together. I hope you really enjoy your day there!