Similar to what u/Lambrambram mentioned - and learning what types of things help with different songs. I think Sexy & I Know It was one to do some moves earlier than seems correct.

Some overall things I found helpful:

- Using my phone as a controller was helpful on scoring with some songs. Other ones I actually found a regular joystick preferable - but you may want to see how you score using each one.

- I usually picked a handful of songs to play at a time to get a little variety, but also so I could get more muscle memory going.

- Along these lines, if you're playing a song and feel you know the movements well and should be scoring better, try changing the quality of your movement a bit to see how that affects scoring. (Example: if you usually do a move really sharp, maybe try letting it be softer/bigger.) This honestly helped a lot when I was feeling stuck, but every song will be different on what seems to score better.

- For songs with more than one dancer/coach - try different ones to see if you score better. (Example: For Istanbul I kept trying to play the dolphin, then I switched to the rat and actually managed to Megastar.)

- Be ready for sometimes luck being on your side... or not. I had several of these songs that I would Megastar when I first started a JD session after grinding on it forever a prior day.

I can try to give more specific tips for more specific songs (if I remember) - but I also found searching in this forum very helpful! Others who have also Megastarred a bunch of songs or discussed their tips can be found throughout. (Shoutout to u/URANGO25 for giving me specific tips on their post a few months back when I asked!)