If you must park next to someone, make sure that there is only a car to the left of you. More often than not, the car next to you is only gonna be the driver, so hence, noone on the passenger side can hit your car.

Avoiding trucks and SUV's is a must (if not for your doors, your mirrors). I try parking next to well maintained luxury cars (cause if they don't give an ish about their 50k car, what makes you think they'll care about yours?) plus if a thief decides to go on a spree, my car looks less tempting.

Sad to say, but I also park crooked so that noone can park next to me. But I only do this when I'm at the opposite end of the parking lot (where nobody parks and you have to walk a mile to where you're going).