There are a lot of implicit computation going on with Meteor's reactivity. Tracker, Session variables, Cursors, Templates etc. They create lots of implicit recalculations that we can easily lose their tails and create a seven-headed dragon that will haunt you! For me, the immediate valuable technique is logging everything that is going to recompute on reactive data contexts (see more here: http://docs.meteor.com/#/full/reactivity).
On CodersTV, I'm starting to send my logs to Logentries, from both client and server. It is useful if you don't want to care about log rotation and other hard disk concerns on small machines. Also valuable if you have a balancer with autoscale and need to send logs to the same entry point. Or maybe if you are using meteor.com server, where it is most valuable.
On Meteor's servers, you can access your logs running the command meteor logs .meteor.com
, but it will give you only the latest logs and you can't tail it making it a hell to cross old and ne