I'd say: do the opposite! Don't plan anything, stay no more than two nights at the same place, jump on a train and see where you end up. Then, if you don't like, just take the next train somewhere else.

I did this twice in my early twenties and it was amazing. I mean, it was absolutely horrible. I slept on bark benches, in Cafés, in train stations, before train stations (until they turned on the sprinklers)... I was picked up by the police because we got lost in a field and more than once I was convinced I'd die. But it was absolutely worth it and both trips became core memories / PTSD trigger.

But seriously, don't follow this advice if you have a kid and are not an immortal twenty-something.