Grasp every opportunity - swim in every waterfall and pool on offer.
Think carefully about carrying your own pack. All our group managed it but it certainly made the hike challenging.
If you are going in the wet season, take your coat everywhere - you never know when you'll get a massive downpour - in fact I wish I'd taken an umbrella.
Pack as light as you can but don't stress if you are a couple of kg over - it's the size fitting in the plane really.
Lots of dry socks is a tip we were glad we followed. Take a really good clear and sealable bag that you can take photos through for those wet but scenic moments.
Although the first 3 days are mostly travelling the rest of the trip makes it worthwhile.
Expect little or no choice for food - almost every meal was just placed in front of us.
When you take your trousers off to do the river crossings you will get bitten - if you react badly to bites consider just getting wet instead.