Get a high quality office chair from Steelcase or Herman Miller. A used Herman Miller Mira Aeron is better than any new office chair for of the same price. Replace the gas cylinder if it's worn. It's relative easy to do at home.<p>Sit/sand desk. Even if you don't use it in standing mode the ability to adjust the height easily is worth the price.<p>If you use a Macbook, get a monitor with complementary resolution.<p>Good lighting with dimmers.