Everyone trusts fortune cookies, and I've been keeping this one for years for the day I could use it. The most important thing to say about Pitot Static Systems is follow the maintenance manual for your aircraft. That means read it before you do the job. Read it again when you question things. Insist your apprentices read it before they help you on the airplane. Make it your business to know that the contracted persons servicing your aircraft are complying with the aircraft OEM requirements.