As a mechanic, what do you suggest as "preflight" checks before driving?
within cap, we have a form that is used every time one of our vans is used for the first time on a day....complete walk around. all lights, back up alarm, tire pressures, engine oil, brake fluid, coolant, belts, etc. 
 for the average driver though.......
once a week, check engine oil level, transmission fluid level, brake fluid level, power steering fluid level, and use a gauge to check your tire pressures. check your lights too. 
 every morning, a quick visual.....tires look ok. it's ok to kick them, as you really can tell if one is low. it'll feel different than the others. 
 i tend to look at my brake lights reflect off of the garage door window as i pull outta my driveway, and cycle the turnsignals as i head up the road. 
 also, since it's cold in a large part of the country now, you should keep some bottled water in the car, a blanket, and possibly an extra sweater. spare battery for your cell phone, some flares, and check your spare tire. 
 i'm sure i've missed a few things.........