Map out what your exploratory testing looks like, compare it to what other testers do.
I'm also using this as a chance to experiment with MindMup.
Here's a first pass at a brain dump of the things I do when I do exploratory testing:
I asked my guild for feedback.
The short answer is, there's lots that could be added to it if you want to go deep enough. Things like consistency with other parts of the product, tab ordering and accessibility, cross browser testing - all good suggestions that would probably branch of Functionality or Usability testing.
One team member suggested they ask themselves what biases they might be falling prey to - which is a great thing to ask yourself! It requires a good self awareness to answer though, too - something I'm going to work on adding to this diagram!