[clarry]

Leave it in gear, that keeps it from rolling off if handbrake fails.

Always depress the clutch when you start. Even if you're in neutral, depressing the clutch reduces the load on the starter motor because it doesn't have to get all the mass of the transmission spinning. (This can also make the difference between starting or not if you're in cold or the battery is otherwise not doing great)

There are times when it's best not to use the handbrake at all.. (let me tell you how I found out: mine is currently seized and I need to get towed, sigh)