If you've run (or read thoroughly) Tomb of Annihilation, are there any extra bits you would recommend preparing?
So any changes you would make, thing you felt were missing or extra content you added to enhance the adventure?
Have read it pretty thoroughly, have not run it. There's a lot of "wandering the jungle" filler...or at least it will come off as filler for a more mission-oriented group OR a group with PCs suffering the Death Curse as written. But a lot of it this "filler" is really well written and seems like it would be a blast in play.
I'd probably start PCs at 4th level, then roughly follow this outline:
Levels 4-5: Port Nyanzaru
Level 5-7: Jungle “finding and getting to the Lost City”
Level 6-8: PC chosen waypoint, like Kir Sabaal or Mezro or a DM’s Guild location
Level 7-9: Lost City of Omu (“exploring, dealing with yuan-ti, getting key”)
Levels 9-11: Tomb of the Nine Gods
I'd consider toning down the Death Curse and making it reduce Hit Dice (instead of hit points) at the rate of 1/week, and if you reach 0 HD, you get undead traits and Acererak gets to use you as a scrying sensor & may attempt to control you (maybe using sentient magic item guidelines). This avoids reducing HP (which can become a death spiral), and doesn't put extreme pressure to reach destination ASAP, thus allowing time to explore (but still keeps up some pressure).