"println debugging" is a tried and true strategy. Debuggers' firehose of information can start to get really hairy when you have multiple threads of execution, for example. "println debugging" (if you have the right tools) can get you 98% of the way there and show you exactly only the relevant information.
A lot of debuggers have a feature where you can stop the execution of threads you don't want to bother with, which I find to actually be more useful than println debugging.
