Unless your last name is Wallenda, don't try any acrobatics high up—184,000 people were injured last year working on ladders.
Make sure the ladder's rung locks (those hooks that grab onto the rungs) are anchored in place and the pulley rope is tied to a rung. Use levelers on the feet if you're on uneven ground and a stabilizer at the top if you can't lean on anything sturdy. To set it at the right angle, stand with your toes at the ladder's feet and extend your arms straight out in front of you; your fingertips should brush the ladder's rails.
Face the ladder as you ascend or descend, and never climb higher than the fourth rung from the top. Once there, keep your hips centered between the side rails as you work. This is one situation in which you don't want to overreach.
Learn all the important points at Ladder Safety Tips