My normal procedure when planning for anything on a remotely large and adventurous scale is to sit and make a Plan A. Research the internet, books timetables, forums for advice and friends for past experience. Try and get down to the most minuscule detail and timing that I possibly can, allowing sensible margins for error and unforeseen acts of God.
Then prepare Plan B, as above but allowing for human nature, both mine and normal people. Build in margins of anything up to 25 percent and allot a star system to evaluate possible failure rates.
When I am happy with those then create Plan C, this allows for distractions and any possibility of something entertaining or exciting happening and includes various algorithms that will make the overall target still viable.
Then, when the great day arrives and I am ready to to undertake the adventure, I put all the plans in the bin and set off
Good luck