How far ahead do you plan your trips?

Not necessarily book but having a solid plan of countries/cities you want to visit in a given year? Do you plan out the year from the start, go into the next year? Or just sort of wing it and travel when you want?

I'm a bit of unique case with this as I plan years in advance (I'm like the Bene Gesserit of travel), so I already know exactly where I want to go 2-3 years in advance, nothing is set in stone and locations may change, but I'll generally keep the same dates. Generally prefer it this way, I like having an idea of where I want to go and I just cant spontaneously travel, I want to have plans and a build up to a trip.