The best spot for fluid collecting, this I found, is in that batch of dots along the river west from Orc Camp node. You can start at the bridge where Lost Small Red Orc is and then move south along the way towards the abandoned building then make your way back draining the trees on the other side of the way, by the time you are back at the bridge, the trees you started with would have reset, and you can loop like this until your energy runs out. There are no mobs that agro and all maple trees are interactive, unlike other zones where only a few are (like the zone around Soldiers Cementery ).

https://www.youtube.com/watch?v=c-IXMGc3i-A ROTT