Travel in the off-season
Especially in Europe, I try to avoid traveling in the peak tourism season. I can’t stand the heat, crowds, and higher prices.
Also, living in a place like Dubrovnik, I really think it is more sustainable to spread tourism throughout the year. I generally try to avoid contributing to the masses that make so many cities unlivable in the summer months.
You’ll also notice that prices for many attractions and restaurants are cheaper in the off and shoulder season.