Select a room with adequate space for the kind of activities you plan to do in your studio. You'll need a lot more space if you're starting a home business throwing clay on a wheel or taking on students than you will if you're a hobbyist who purchases unfinished ceramics to paint. A spare bedroom, workshop, garage or enclosed patio are ideal. It should have windows for good ventilation and hard floors that you're not concerned about getting messy are ideal.
Paint the walls if they need it. White is the ideal because it brightens but ultimately it is a matter of personal taste, so choose colors that you like. Use semi-gloss or glossy paint to make clean up easier.
Select a place for a kiln, if you want one. A kiln is the biggest consideration because you'll need to take fire safety precautions, make sure you have adequate wiring and install proper ventilation for the type of unit you are getting. Set your kiln up according to the manufacturer's guidelines and recommendations.
Pick a corner with an outlet to set up a pottery wheel if you plan to be working with one. Place a stool near it. Set up a table nearby to keep tools within convenient reach and for when you're not working on the wheel.
Install a sink, if necessary, with a clay trap to prevent clogging the drain. A sink can be a major investment if pipes need to be routed to a room. If you're going to be a professional potter or have students, it could be a wise investment. If your studio is somewhere you have access to a hose, it can suffice. An avid hobbyist, however, can get away with two to three large buckets in a corner where you can haul in some water to wash your hands and tools .
Turn on the lights and assess if there is adequate task lighting in the room. Move from one work area to another to ensure they are well lit and you're not casting a shadow over your work. If not, install additional fixtures or work lamps.
Hang sturdy shelving, or purchase strong shelving units. Consider all the storage you will need for not only supplies and tools, but for work-in-progress and finished pieces. Your storage needs will largely be determined by how much you plan to produce in your studio. It's better to have more to grow into than to find yourself coming up short. Set your storage and equipment up to create an efficient production line so you don't find yourself scrambling back-and-forth a lot.
Hang some inspirational artwork or other personalized items in your home studio. Create an environment that inspires you.