How do I troubleshoot Siri? I just got my 4S yesterday (thanks AT&amp;T for the early upgrade date!).  I've noticed two problems with Siri and I don't know any good methods to troubleshoot.

1) When I hold the phone up to my head from the home screen, Siri starts, beeps and etc.  When my wife holds the phone to her head, nothing happens. 

2) I've tried to set "geofenced" reminders -- "When I leave here, remind me..." sort of stuff.  I've not yet actually gotten the reminder to trigger, even though Siri told me it was set.

I'm sure I'll run into further Siri issues as it becomes a bigger part of my life.

What I'm asking for is not specific answers to the problems listed above (though they would be cool).  I'm trying to get a better feel for generalize Siri troubleshooting techniques.
There isn't a lot you can do about holding it up to your wife's head, perhaps it isn't close enough. You will notice that if you try to fool the phone by holding it up to your had or arm siri will not activate. 

As for the geofenced reminders, you need to have location services turned on for reminders.

You will also need to set the address in your contacts, so add your home and work address to your contact.

For troubleshooting you will really need to look into the apps you are trying to control from Siri, as Siri itself is not an app, it is part of iOS. It is each individual app that will need to be looked at when troubleshooting.

Remember that Siri is still in beta and you can expect some teething problems with it.