By far the most important tip is to expose yourself to many perspectives–particularly if your trip is via Birthright or other one-sided viewpoint. Go out and listen to Israeli Jews and Palestinians. Visit secular and religious sites. Seek out peace activists. Take the short bus ride from Jerusalem to Ramallah. Have a falafel in an Arab community like Gush Halav or East Jerusalem.
You cannot have a real understanding of Israel without having encounters with people who have been affected on all sides of the conflict. Embrace it. You’ll have a much deeper and more memorable trip.
On our first trip we set up appointments ahead of time with leading figures in the Israeli Jewish peace movement and stayed in both a Palestinian village and an Israeli West Bank settlement (as well as a Palestinian hotel in East Jerusalem and a Chassidic community of mostly formerly secular immigrants from the US.
On our second trip (chronicled at http://frugalfun.com/israel.html ), we stayed in a Druze village, had an accidental encounter and interview with a villager forced from his home in 1948 when he was 11, who was conducting a one-man Occupy movement in his native village (now a national park), and attended a concert with both Israeli and Palestinian performers, including a Chassidic rapper-rabbi and a ten-year-old Bedouin boy.
Contributor: Shel Horowitz