Obtain a safe ladder. Trade-standard ladders are best, rated at 225 pounds, feeling more secure.
You have learned to use your ladder safely, make sure you do. When setting up, always be sure it is on level and solid ground. If you are on dirt or grass, you should use the spikes of the feet (if applicable) to dig into the soft earth. It is also very important to lean the ladder at the correct angle. There is a rule of thumb to obtain the right ratio: for every horizontal foot, you have 3-4 feet of rise. So if against a wall, if your ladder is extended to a total 20', you want to base of the ladder 5 or 6 feet from the wall. Stay close to the recommended angle to avoid slipping.
Reaching the soffit from the ladder should be comfortable, and you should not need to reach. Set it up at a height that is just below the area you need to work. Your body should stay centered on the ladder, and still be able to work effectively on the surfaces scraping and painting. But always keep one hand on the ladder, and scrape or paint with the free hand. This can be tedious work, but you will be sorry if you lose your balance!
Get paint can hooks as you don’t have an extra hand to hold a can of paint when working at heights! Be careful if it is windy. Wind can be quite strong 30' off the ground, enough to cause you to lose your balance. Do not move the ladder when it is fully extended; take the time to drop it down. Always work with another person to assist with the ladder.
Using a ladder is important in the painting field, proceed methodically and never rush or skip steps that could jeopardize your safety.