Aside from your chair, there are a lot of ways to make you comfortable (and healthy) while working for long periods. For example, if you work on a laptop, consider a laptop stand to ensure the screen is at eye-level. If you’re an illustrator, consider investing in a stylus.
Lighting is a major part of your work environment, and bad lighting can cause eye strain, blurred vision, insomnia and SAD (Seasonal Affective Disorder). If you can, find natural light. Position your desk near large windows that face north or south (rather than east or west) to prevent glare.
If you’re working with artificial light, an angled desk or floor lamp is better than relying on ceiling lights, which can be scattered and dim.
Have a backup
Juggling multiple projects means saving lots of important files and making sure nothing fails along the way. Invest in a good backup device to keep your files stored safely and securely (and keep yourself sane).
Some designers love an empty desk. Others go all out with decor. Whatever you do, make sure your workspace makes you feel inspired and motivated (not deflated and tired). Try injecting colors that have positive psychological effects. For example, yellow and orange can boost energy. Blue encourages inner calmness.
Or maybe hang up inspirational images like personal photographs from recent travels or beautiful magazine pictures. Whatever makes you feel motivated, put it up!