While a Home Based Interior Design Service is run from your home, much of your job requires you to go to a clients home, office, business or other space, in order to determine and evaluate the client's needs.
Residential and Commercial Interior Designers require different types of marketing techniques, and you should be aware of the differences.
You should also know that in order to call yourself a designer, you may have to be certified. Without formal training or certification, you may have to use the title "Interior Decorator" instead, which is fine. Because more than 20 states now require certification, you'll need to take and pass the exam given by the National Council of Interior Design Qualification (NCIDQ).
You should be familiar with using all different types of materials, colors, fabrics, building materials, furnishings, etc. and be adept at using Interior Design software.
You need to be aware of the latest trends in the design world, and have a good eye for proportion and color. Your skills and experience will be your main tools, so invest wisely in them.