Wild camping in The Netherlands is illegal (90 Euro fine). So you do need to pick your spots. I can only afford to stay in hostels some of the time and couch surfing only goes so far so inevitably, I need to camp at some point. I do feel bad about dodging the ‘tourist tax’ (do I?) that is levied on hostels and hotels but I’m poor. You don’t need to look too far however to find a nice wooded area in Rotterdam, about 5km from the city in any direction apart from East.
It may be just off a main road but as long as your hidden and have earplugs, your sorted. Watch out for main pathways that may be used by dog walkers or kids going to school.