Most may only know the annoyance of calendar alerts with beeps and pop-up windows. What is little known and even less used is the fact that the Mac OS X Calendar application can also open files or run applications as an alert function. With the good old Automator you can turn AppleScripts into executable applications. If you combine all of this with OmniFocus, you arrive at what Sean Korzdorfer is demonstrating in this GitHub repository: Creating project (templates), tasks or task groups with a calendar alert.
If you have regular meetings or a fixed checklist when preparing longer business travel, you can use this approach with a calendar alert that goes off days or even weeks before the event to automatically create the right tasks or project in OmniFocus that allow you to be prepared.
Just keep in mind that the Calendar application needs to be running to run the application the alert is associated with. However, it should also execute the alert the next time your Mac is running after the original alert time.