This is an itinerary to avoid the big tourist destinations in Bangkok and the eastern Thailand where most visitors will visit Pattaya, Kog Samet and Koh Chang, I recommend many other options much more local and without the crowds (yet).
Check my personalized itinerary service if you want a fully detailed itinerary based on your dates, budget and interests. I'll include hotels for you, restaurants, bars, transportation, best spots, all tailor-made!