Respond to inquiries as quickly as possible.
Perhaps you are not the only designer to whom the customer wrote. If you delay with an answer, there is a chance that the client is already discussing work with another contractor
Know the value of your work and do not be afraid to voice it.
Many beginners are afraid to name a price because they think the client might "flip off". Set a minimum for which you are willing to work. If the client is not satisfied, offer options with a lower cost. Be flexible
Listen carefully, ask leading questions.
Your task is to understand what the client wants and offer an effective solution. Remember that he comes to you with a "problem" and pays for the result.
Set realistic deadlines.
It can be difficult for a novice specialist to talk about deadlines, since it is not yet clear how much time he will spend on a particular job. Call the deadlines with a margin. It's a shame if, because of such a trifle as missed deadlines, your reputation that has not yet been established will suffer.
Keep in touch with the client throughout the work, inform about the stages.
Let the client know that the work is going on, and you are conscientiously fulfilling your duties