My suggestion would be to NOT try to squeeze a lot in. I've taken several trips with first timers and I have found they can be easily overwhelmed. WDW is a sensory overload even for seasoned pros. I've also found that people who tell me they did not enjoy their trip tried to see it all in a relative small amount of time. After I ask a few questions, I start to see that they spent all day at the park from open to close, didn't take breaks, didn't stay on property, waited in lines longer than hour waits, etc. The best thing to do is to make 3 lists. These lists can be on paper or simply mental. But prioritizing attractions into "must see, would like to see, and could take or leave" is important. Some people thrive in non-stop, commando park touring but it can also cause crankiness and can take away from the overall enjoyment of the trip. Don't try to force first timers into doing/seeing something because it's a "must-see." This can cause some resentment. Just try to go with the flow!
Now, to what you were REALLY asking. I'm not sure I can add anything besides the obvious you've seen discussed here (dole whips, etc.) The last few trips I've made it a point to stop at the Basin store at DTD. I buy a few "bath bombs" and use them back at the resort to soak after a long day. Touring the resorts is also a lot of fun. Something new I'm planning to do on my trip in November (staying at WL) is to tour the monorail resorts for lunch. Stop at one and get a salad or appetizer, main course for the next and dessert at the third/last resort. That's all I can think of for now! :wave: