Rules

Most standards and practices are really guidelines and rules of thumb. Decide they are strictures that must be followed to the letter and you ain't gonna be doing nobody no good, nohow.

Review and validation

Reviewing a deliverable - and validation of actions taken as a result of that review - should be done by the same person. Otherwise you risk a never-ending cycle of new change requests. And (and this is very important to the Facebook generation) you may never get your validation.