Following our first Lessons Learned, here are some items that are good to keep in mind during construction.

Balancing personalities is an art form, especially during the chaotic times when you realize a mistake has been made at 4 PM on a Friday. Establish a courteous relationship with your GC and subs, be very clear about your expectations at the beginning and express your satisfaction as much as possible.
Be more thorough about material pricing with the contractor (garage siding, concrete flatwork,etc.). If you are at all like us, you will never be satisfied with the most basic or lowest level materials, so be clear about that when you select your finish material.
Listen to your sub-contractors, but don't let them make decisions on what they are going to install, just because they are familiar with it and/or have done it this way a thousand times. Be prepared to hold your ground and push them if necessary.
In the rush to get a sub on-site at the correct time in the schedule, don't take whoever is available. Get the best person for the job and get referrals. It's best to look at their work on other jobs and contact their references.
Don't feel guilty about making a sub tear out something if it's not right - if you've specified and documented your details -- and it's not built right, then be a stickler, it's your money.
Never assume a sub can read your mind. Be very specific, if you are making an on-site decision. Mock things up, measure and mark if necessary. Never assume the subs are going to know where you want your heat registers, hooks, towel racks, lights. Be available and around to help with all layouts that are important to you (lighting, fixtures, tile, etc). Sometimes it looks right on paper, but be prepared to make changes on site.