Sit like a powerlifter for the rest of your life.
Hope the title gets you to take a look. A lot of people come in with aches and pains in the knees or low back at an older age but can't pin point where they hurt themselves. Sometimes it's the slow drip that carves a mountain, and sitting down / getting up your entire life without ever giving it thought may be the proverbial straw breaking your back. Learn to box squat and use it to sit and stand for the rest of your life. It doesn't look as odd as it sounds, and at least you wont be one of the elderly that has to grab the table and do a good morning to sit or stand.