1. The whole food thing.
While feeding your crew can be a morale booster, serving them crappy food will have the opposite effect. After hours of hard work, nobody wants to eat a tasteless, dry, and cold ham sandwich (man, do I hate those!) or some cheap fast food. Eating should be a pleasant time, so don't settle for the lowest common denominator of edible food.
If you know anyone who can cook, consider getting them to cater for your shoot. The amount of money you spend on ingredients will almost always be cheaper than paying $6 per person to eat fast food. Even if it wasn't cheaper, the quality of a good meal is worth spending a few extra bucks.
Besides the main meal(s), it's always a good idea to have plenty of these around. For water, I advise getting the smaller water bottles instead of the regular sized bottles. I've noticed on set people will grab a water bottle, take a couple sips, lose the bottle, then go back for a new bottle 10 minutes later. That ends up wasting a lot of water and leaves a bunch of half-filled water bottles laying around.
2. Handling your crew.
This one's a given. Sure we might hear stories about how some of Hollywood's biggest directors are huge jerks on set, but that's one thing I wouldn't advise mimicking. In addition to you showing respect, make sure they are also treating each other with respect. By "make sure" I don't mean to go out of your way to be a babysitter to your crew, but that if you do notice disrespectful behavior to not stand for it.
No one likes a control freak. If you can't trust your crew to do their jobs, you probably shouldn't be working with them in the first place. It's normal to want to make sure the work is being done right, but breathing down everyone's neck and questioning their every move is a recipe for disaster. Learn to give your crew space to do the job you brought them in to do, and they'll perform significantly better.
There is break time, and there is work time. Don't accept people taking breaks while others are working. This is a lot less common on professional shoots, but I see it on amateur shoots all the time. For some reason, some guys, usually grips, always decide that their help isn't needed and they sit around on set socializing while others do the work.
You probably got into Filmmaking because you thought making movies was fun, so create an environment that reflects that. Have a good time whenever you can. Tell a joke; laugh every once in a while. Being on set is stressful as it is, so don't add to that with an overly serious attitude. Make sure you have a good first AD though, so you don't get too carried away!
3. Handling yourself.
You always know what you're doing. Always, even when you don't, you do. Are you clueless about what to do next? Of course not, you're the director. When your crew throws doubt your way, you always respond with "I got this," because you do got it—after all, you're the director. "Have a little faith," you tell them, "I was born to do this!"
In film, everything that can go wrong usually does, but some things can be prevented by simply doing your homework. In last week's post, Eric mentioned how it's not as simple as to "just do it," but to plan it beforehand. You can't expect anyone else to put in more work into your own project than you are, so don't drop the ball on pre-production. Do the planning that's required of you, and your shoot will be better for it.