For those of you who have non-flip cell phones, how do you avoid accidently pressing buttons?

I’ve always had a flip phone, but recently I’ve been thinking about getting a “candybar” style phone. I like the flip because there are no accidental calls. I’m aware of the keyboard lock function, but what if you forget to lock it? Does it lock automatically? Is it an annoyance to have to lock it every time?

I just know I’m gonna end up calling my boss late at night or something.

Just in case this makes a difference, the phone I’m considering is the Nokia 6301.