>>1716768The first thing to try is contacting a land owner, explaining to them that you are looking to camp out and will do so in a way that doesn't leave a trace. A lot of people are cool with this ime.
The next thing to do is to find a remote place where the chance of someone who cares seeing you are slim. Then just wait till the evening to pitch your tent, keep any fires you have small, and pack up fairly early in the morning.
Not many people actually care about someone camping in the woods, just make sure that before you leave you haven't left any visible trace.
This is what I do in the UK where camping is also technically illegal.