In most cases, we shy away from this. From our experience with previous clients, what tends to happen is they begin to pick apart the design and try to get certain things on their own or from people they know that look similar. This causes delays for us and even changes how the final design looks which in some cases has a negative impact on the final outcome of your design. The success of your design is the sum of its parts by using our team that we trust and can manage.
For example, if someone says their brother is a painter and will do all the painting, then we have to wait until all the walls are painted before we can install anything on it. If the client is most likely getting a great deal from their brother, then the brother would do it on their own time when they are good and ready.