This will be year #13 for me in Assisi as a Director of the music festival "Assisi Performing Arts" so I'm a bit biased. During the day there are always plenty of tourists but only on a couple of streets - anything with direct access to the Basilica San Francesco. The rest of the medieval city is waiting to be explored and appreciated. It's quiet, peaceful, plenty of amazing views both up and down. The art, history, architecture are truly inspiring. The churches are filled with beauty and history. The Roman and Etruscan ruins under the city are well worth exploring. In the evening the tourists are gone and the city is bathed in soft lights. That's the perfect time to just "be" in this very special atmosphere. This is a very safe and friendly city. Feel free to wander anywhere.
Orvieto, Spello, Siena, Lake Trasimeno, Perugia, Gubbio, Spoletto are all within easy reach. For me, the evenings are for Assisi though.
If you're there between July 4 and 19 come to one of our concerts - plenty of chamber music, opera, sacred, and Broadway.