Coming from a background of both tech support and DevOps, the most useful question that I tend to ask on every inbound issue is "What have you tried to resolve the issue yourself?" This is usually followed by "What workarounds are available to you while we work to resolve the issue?" These questions are equally valuable to the reporter and the supporter, and sometimes lead to misunderstandings resolving themselves. Having them as part of the template also discourages "We've tried nothing and are out of ideas" bugs from being filed.