I've pretty much decided that the guiding principles are:
1. ALWAYS have your firearm with you. Whatever it takes to make sure it's always there, then be prepared to make some minor concessions. If carrying it on your belt causes you to leave it behind .1% of the time, then that's not adequate.
2. Carry in tandem with a partner
3. Understand that a firearm doesn't solve every problem and it's better to observe the three S's rule.