Follow this formula and your design interior
1. Understand requirement of client.
2. Making things out of this requirement,
3. Putting these things at better places.
4. At final step, start making it beautiful.
Imagine, imagine, imagine, your imagination is king in interior design, if you are not good at imagination, you might be fail in interior designing, imagine different colors, lighting, material, curves in mind, start making it beautiful, lighting, colors, material, curve, whatever you have in your mind, place it at your canvas, than make a master piece, this will be approve by client guaranteed, because this 100 % fulfill your client requirement and also its beautifully design, this is the formula of designing.