Be fat.

My youth pastor, Toby Dix, used to have a saying whenever we would go on missions trips and other events where it would be easy to think that it was all about us.   He would say, "Remember guys, be fat."

To be FAT meant to be flexible, available, and teachable.  

And now, 5 years after high school, and- if my time working in churches has taught me anything- for the rest of my life, this lesson is relevant again.

It doesn't just apply to those who dedicate their lives to working in a church as their main occupation either (I don't want to say "minister" or "missionary" or anything, because we are all called to be that, regardless of our job title).  This applies to a shampoo salesman just as much as a worship pastor.

Flexible
To be flexible means to be willing to change details at last minute.
 I remember when my dad was a youth pastor and took the youth to Charleston on a mission trip.  He and the team had spent weeks planning out games and witnessing tools that would be effective.  They got down there, and, well, things didn't go to plan.  The kids they were working with were wild, didn't play the games like they were planned.  The team had two options: 1) Stick to their plan and force those they are trying to witness to to fit into their schedule, OR, 2) step back, and reevaluate everything.  And they did.  They had to be flexible in order to be effective.  And so do we.

Available
To be available goes hand in hand with being flexible- you have no clue what will happen, so you have to be available for action.  Available for whatever may arise.  Your job title in the church may be "family pastor", but someone comes to you and says "The toilet is overflowing."  You can say to yourself (or to the person, if you so choose) that it isn't your problem, that you are the family pastor, not the janitor.  Or you can be available to help and serve God as He decides.
My Bible teacher in high school moved away my senior year to pastor a church.  He moved back a few years ago and went back to his old church to serve.  As a janitor.  When I asked him why, he said he was doing what God was wanting him to do, and being available to God to do with as He wishes.

Teachable
You aren't the expert.  If CNN doesn't call you when something happens, it means there is someone smarter or better informed than you in whatever the case.
Most of the time, on a mission trip or in serving God, you learn more than you teach.  Why? Because we don't know it all.  I have never been involved in a church/ trip where I didn't leave having learned something.  Whether it is new ways to mix Kool-Aid (ask Walt Tanner), or simply letting God teach you something about Himself.  But I had to be flexible and available in order to be taught.  And I had to be willing to be taught.

I'm sorry this was on the longer side, but next time you are serving, in any form, remember to be fat.  Remember that it isn't about you, but a much bigger purpose.