Preparing for Trial Early

I am a fan of preparing early for trial to the extent possible.  I try to prepare what I plan to present a week or so before the discovery deadline.  Many times I have found that I need to add a witness, get some more documents, or supplement additional discovery responses.  For some reason, many attorneys think they can show up with stuff at trial that has not been disclosed or send it the day before.  I have successfully had a whole bunch of adversary evidence excluded that way including an expert witness who had been brought in on a high retainer.  There is no harm in preparing too early, but too late can get you burned.