Before hiring a decorator, overall, if you are not going through references, ask and compare several estimates.  This comparison can help you to save a lot of money on the same job.

It is not recommended to opt for an estimate that is too low.  Review the minuscule details so that you are not deceived.  We are telling you this because normally a poor quality job is behind an over-adjusted estimate.  

Maybe the materials are not adequate or the time given for the job is shorter than what is desirable and therefore the quality will not meet requirements.  Also, it may be that the work staff are not optimum or capable of carrying out a job of that calibre.  Also, before the job begins, you should establish and be very sure of what it is they are going to do in the house, the materials they are going to use, their costs, the time the projects will last.  Therefore, it is very important that the estimate be completely detailed.

Keep in mind that at the end of the job, if the price has risen or if something did not turn out as was established in the estimate, this will help you make a claim and have the upper hand. From the former advice, we can derive the following: Never pay for the materials or the job in advance.  This type of work usually stipulates a payment before the job that will be paid in full at the end of the job if both parties are satisfied with the result.

Of course, all these are only preventative measures.  In the world of interior design, there are excellent workers, who are very professional and completely legal.  But, as in everything, there are always exceptions.  Therefore, you must take precaution.