When I sat down to discuss my experience, I was very nervous because I worked for state agencies for my entire 'engineering' career. I was told that licensing boards frown upon the work experiences of govt-employed engineers. Fortunately for me, I had jobs that were very technically oriented and included aspects of design as part of the work product.
Tips:
1. Make an outline of your work experience. Try to rank it in terms of becoming progressively more responsible for work or assignment of projects (or other work) that was more complicated or difficult in nature. Especially pick out of those experiences cases where you were involved in DESIGN - that is a big component that the licensing boards are looking for in your application.
2. Be HONEST! You don't want to reflect something in your experience that you didn't do or stretched too far. Once you have added a blemish of credibility to the state board reviewer - it will be an uphill battle to get your application deemed complete.
3. Select words that concisely describe your activities - responsible for ... , design .... , etc.
I spent nearly a week on the work experience aspect of my application because I was so concerned it would be rejected. In retrospect I don't know if I needed to have spent the time that I did, but I was at least able to make a good showing to get approved for the exam.
Good luck! Nobody likes to have to sit down and describe these things - everyone struggles a little. Just set aside some time and get 'er done!
JR