You can only review what you get. Provide illustrations, give awards to projects that are sensitive to neighborhood concerns. Providing adequate information will help produce applications that approximate what is desired. Design review inherently involves editorializing. Value judgements and choices must be made.
Communities are diverse.
Many places have no character or qualities that are desirable to reproduce, and in those cases decisions about the type of design that is desirable must be made. Design review needs patronage, a core of supporters who stick with it over time. The support is necessary because in the process a lot of people will not be getting all they want. The supporters will help shore up the process when those who have not gotten what they want from it become frustrated. A review board of highly respected members can play this role, or there could be a group appointed to monitor and evaluate the process that also assumes this role.