The skills that I think some of our employees lack are basic problem solving skills.  I think we need to help them with generic principles for what to do when you get a new ticket:

1. Do you understand the problem?  If not, ask other staff members.  If still no, ask for more information.

2. Verify the facts.  The librarian says the circ rules are correct.  Are they really?  The librarian says she is choosing the active budget.  Is she really?  Go and check every fact yourself.

3. Can you reproduce the problem?  Try it on master.  Try it with a test patron on customer's server (if possible).  If you can't reproduce the problem, ask for more info.

4. Are there related system preferences that might be affecting Koha's behavior?  Check the manual, check with colleagues, ask in IRC.

5. If you find the problem exists in master, you've got a bug.  Check the community bug tracker to see if you find anything similar.  If yes, put the link and reassign the ticket.  If not, report the bug, add the link and reassign the ticket.

6. If you find that the problem only exists on customer's server, this is where it gets harder.  Try comparing to other customers' sys prefs, etc.  Get advice from colleagues.  [Other troubleshooting strategies here - need some more advanced advice...]