I an anal-retentive so I plan it all out in my head. Then get everything ready ahead of time. This way i am less stressed and we usually do not forget anything.

However, i do like just taking off at the spur of the moment. Usually, for a short trip to a city that has everything i need. Like deciding on Friday to head to Vegas for the weekend. Throw shit in a suitcase, go to airport and hop the next plane, pick a hotel in the cab from the airport and enjoy the weekend.