Consider a room, which is perfectly design, but not fulfilling your requirement, what this design called? Design Failure, Interior designing is not for designing home or office just to look gorgeous, vital factor is to fulfill requirement while keeping it gorgeous, so interior designing is to balance both, designing aspect and requirement aspect, if you just start designing by making room space gorgeous, your client might rejects your design. 

First step in the interior designing is to know the requirement of your client, its always be a better thought to make questionnaire, place as much detail questions as you can do, sit with your client and observe his personality, invite him or her in your office, when you reckon you fully know client requirement, now start your drawing, first only draw basic requirement, no fancy curves, nothing, just simple basic design, just place things in better places, measurement aspect and that’s all, when you end basic design, now start making your design gorgeous. 

Imagine, imagine, imagine, your imagination is king in interior design, if you are not excellent at imagination, you might be fail in interior designing, imagine different colors, lighting, material, curves in mind, start making it gorgeous, 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 perfectly design, this is the formula of designing,

Know requirement of client. Making things out of this requirement, Putting these things at better places. At final step, start making it gorgeous.

Follow this formula and your design will be a winner design.