I have been in lots of trials. It's hard to just give basic advice because all trials are different. Ill I can really tell you is be very slow and think a few questions ahead. Remember if you ask a question it will usually be answered very specific. So if one part of the question is wrong, you will get the wrong answer. If its Robbery you have to prove intent. Robbery is a specific intent crime. Its always nice to show motive, and the present ability to commit the crime. Your case should have a good witness to identify the suspect. Its always good to have the witness openly identify the subject/subjects in court. There is also the witnesses vantage point and how well he was able to see the subject. Distance is good. Hopefully no obstructions, and a good face shot never hurts. I don't know if this is a store, person or house. All have different additional thoughts for evidence. Remember if it isn't testified to in court, it didn't happen. There is tons more but I don't want to rant too long. I wish I could be there it sounds like a lot of fun.