Planning? Are you kidding me? I just get on my bike and go. Well, maybe I pack up my bike, put it on a plane, and fly to a pre-thought-of destination, but that's about the extent of it. Generally, anyway.
I think a lot of it is that we've toured so much now that we can "plan" pretty quickly. A quick look at a map and we can pretty well judge how long it will take us to make it from poin A to point B. We have all our gear and such, so we can hop on and go.
What we found took all the time for this extended tour we're on now was the preparations for putting our lives on hold for so long. We had to figure out what to do with the house - contact a property management firm, remodel the house for renters, pack up all our stuff and get it in storage, etc... We also had to deal with all the bills and get everything on auto-pay or arrange for other payment. There were a gabillion little things to do like that.
In the end, we spent a frantic year preparing for this trip, but very little of that was spent actually planning the tour itself.