If you're touring from Amsterdam to Italy, I'd recommend finding established campsites and camping there at least every couple days. They're all over western Europe (there are at least 10 within 30km of Amsterdam alone) and are really cheap (usually around 4-5 euro for a tent and 3-4 euro a person beyond that). They have running water, showers (often the pay kind, but it's worth a euro for the cleanliness), and other amenities. I wouldn't recommend stealth-camping in Europe, because it's sort of hard to be stealthy. Any woods you find will be overrun with trails, and you'll most likely get run over by a German MTBer looking for some good single-track.