I really depends on your personality, length of stay, where you are staying, etc. I've been going for over 40 years and am less than young (O.k. I'm old, 68). I go solo often but through the years have gone with my toddler son who is now grown and takes his toddler daughter and other family members. I don't plan a thing, nothing. No ADRs except day of, I don't buy LLs, I don't know when I'm getting to the parks or when I'm leaving. My entire trip is go with flow and on my own time and what I'm feeling like doing. Even when my son was young, we weren't ride centric. We have the advantage of having been going since before even FP so we got used to waiting in lines. I tend to wake up very early, around 4 or 5, at home or on vacation. I'll sometimes get up and make a cup of coffee and just lay around and read or if I have a balcony sit on the balcony and enjoy the resort waking up. Sometimes I'll go back to sleep, sometimes I'll take a walk. If I go to a park around rope drop it's not normally to ride a ride, it's to get breakfast and I sit and watch the park wake up. I'll go to whatever ride I feel like riding and if it looks like the wait is too long, I'll move along. Too long just depends on my mood. I have an AP but even those times I don't, I always have PHs. I'll usually leave my morning park around lunch. Depending on the park and my mood, I may or may not have lunch there or at the resort. I go back to the resort and either go to the pool or just rest in my room. How long, again depends on my mood (see a trend?) and then I'll head out to a different park. Rinse and repeat. When I'm at the parks I love to explore every nook and cranny, enjoying the details and finding new surprises. If I'm in the mood for a TS meal, I just hop on
MDE (usually during my afternoon break) and see what's available that night. Since I'm an adult and not picky, any park/resort/time is fine. Again, just depends on my mood. I've never not found an ADR for day of, is it at the "must do" places? Sometimes yes, sometimes no. It's a great way to find new restaurants. I tend to stay at the Epcot resorts (most of the time Swan/Dolphin) so I hit up Epcot every single day of my trip. I've been known to accidently hit 4 parks in a day, just deciding this park is too crowded or I'm not feeling it and moving on.
It's all about my mood for me. Too hot, back to the room. Too crowded, go to a different park. Hungry, ice cream sounds good. Oh look, FOLK starts in 15 min. and I'm right here, think I'll go see that. Wait, I've never been down that path before, wonder what's down there, let's see. Hmmm, that bench looks mighty cozy and there is a stand to get something to eat/drink right there, think I'll just sit and enjoy that.