I try everything I can to avoid crowds. My strategies:
* Pre Park Opening ADRs, followed by an hour or so of the park, then break and go relax (a mid day break is crucial to my enjoyment; it is easy to get tired and frustrated if you go full speed - especially if older). Go back to the park or another park around 4 or after. I find evening crowds can be pleasant. For example, we usually get a PPO ADR for Garden Grill, finish around 8:45, walk downstairs to Soarin, they almost always let you on early, go immediately next to Test Track, then Mission Space. After that, it's easy, or a good time to leave the park.
* Doing opposite of what everyone else is doing. While I enjoy the parades, I'd rather be doing other things while the crowds are down. We watched the fireworks from Fantasyland last trip, and while we did not see the castle projections, we found the experience to be quite unique. I felt like I was in the middle of the fireworks. Then we headed right away to an attraction without the crowds.
* Rope drop or EMH. I also have no problem paying for events which have limited crowds. Back when they had evening EMH, I found the parks to be very easy to move about and see the attractions.
* Getting the crucial fps. Refreshing can work well. I was able to get (6) 7DMT fps and 5 Peter Pan fps for the next day while waiting for my dining reservation (and my family to ride a roller coaster I couldn't ride).
* Rain is your friend. Always carry a poncho. Last trip, all the attractions in Toy Story Land were practically a walk on after a pretty good rain, even Slinky Dog Dash. We had reservations for the EMM Toy Story Land the next morning and were able to cancel since we did everything without any major wait times.
We have been at the most crowded weeks and manage by doing these things. We also have the most fun when we loosely plan. It is definitely beneficial to have a plan, but be open to change those plans when a better opportunity presents itself. Don't get too hung up on dining reservations. So many people change their plans, most restaurants have last minute openings 1 or 2 days before. I check for reservations all the time, pretending I'm at Disney World, and practically everything is available a day or 2 before, even Beaches and Cream, Chef Mickeys, BOG, etc.
ETA: If you don't have kids, try to carry everything you can in your pockets. It's very pleasant to not have to go through the bag check. The plastic ponchos can be folded up to be very small and flat. I carry stick roll on sunscreen.
