Petrol station hitchhiking
Petrol station hitchhiking is especially great in countries where there it's not allowed to hitchhike on the high-way and where there are enough but not too many gas stations on the highway. At most gas stations everyone is mostly going your direction, though you have to be aware of high-way crossing.
In Germany you should possibly avoid the "Autohofs", they're not great, since there is no clear direction.
It can be useful to connect to the people who work at the gas station. It makes it less likely that they will send you away.
In Italy you have to be careful. It's illegal to hitchhike on the autostrada, it's a bit unclear if it's illegal on the gas stations on the highway as well.