Hitchhiking in Europe is fun. There are many small countries, highways in the West are good, and hitchhiking is relatively safe. Germany and England are very easy. Germany for the large distances for a single lift, and the possibility to go really fast (no legal speed limits on many highways). England for the relative short time for waiting. Most other countries are at the European average (rather easy), e.g. the Netherlands, Belgium and CIS-countries. Some other countries are considered bad for the long waiting times like Spain and Croatia, but even there you might get a ride with patience. Some people skip a country after standing in one place for over two hours. When this happens more than once on suitable places for hitching, this is reasonable.
Of course, you won't go on the road without a map. For all of Europe but the East, the Marco Polo Euro Atlas is great. It contains detailed information about gas stations on highways, without unneeded stuff like an index or city maps. You can find it in Slovakia.
For online usage:
Hitching is rather safe in Europe. However, a woman alone takes a higher risk anywhere south of the France-Switzerland-Austria-Hungary-Ukraine line.
Tips for each countryEdit
In Western Europe it's pretty easy to hitchhike.
There are not so many cars in Northern Europe, which consists of Finland, Iceland, Norway, Sweden, and Denmark, but that makes it nicer to hitchhike, if you don´t mind walking. You can legally pitch your tent almost anywhere outside of cities.
Eastern Europe is great for hitchhiking. In many countries there is an active hitchhiking community. It might be a good idea to blend in with the locals. Don't dress conspicuously western, but do make it clear that you are a tourist. Many people love to get to know more about your culture.