Proverbs 27:18 Honorable service

The one who guards a fig tree will eat its fruit,
    and whoever protects their master will be honored.

You might have heard someone make a comparison before --- starting with one thing that was certain, and then noting that the other will happen, too.
Something along these lines: "As surely as the sun will rise tomorrow morning, I will get it done."  Since we assume that all's right with the world, and that the sun will rise as it always does, we conclude that they are quite determined to do whatever they have promised. 

I think that is what Solomon is doing here. It was obvious to him that whoever tended a flock would use the flock sometimes for milk or meat, and that someone who tended a vineyard or a field would make use of the products that they were given responsibility for. It's even noted in the Bible:

 Who serves as a soldier at his own expense? Who plants a vineyard and does not eat its grapes? Who tends a flock and does not drink the milk?  I Corinthians 9:7

So, Solomon is saying here that it is also every bit as certain that "whoever protects his master will be honored." The Hebrew word that is translated "protect" here in the NIV also has meanings of "hedge about with thorns," and "guard, attend to, wait upon, serve."

Jesus told us:

Whoever serves me must follow me; and where I am, my servant also will be. My Father will honor the one who serves me. John 12:26 

How can we best serve Him?  Let's look at Romans 12:

Therefore, I urge you, brothers and sisters, in view of God’s mercy, to offer your bodies as a living sacrifice, holy and pleasing to God—this is your true and proper worship. Do not conform to the pattern of this world, but be transformed by the renewing of your mind. Then you will be able to test and approve what God’s will is—his good, pleasing and perfect will.
 For by the grace given me I say to every one of you: Do not think of yourself more highly than you ought, but rather think of yourself with sober judgment, in accordance with the faith God has distributed to each of you. For just as each of us has one body with many members, and these members do not all have the same function, so in Christ we, though many, form one body, and each member belongs to all the others.We have different gifts, according to the grace given to each of us. If your gift is prophesying, then prophesy in accordance with your faith; if it is serving, then serve; if it is teaching, then teach;  if it is to encourage, then give encouragement; if it is giving, then give generously; if it is to lead, do it diligently; if it is to show mercy, do it cheerfully. 

^{We must determine what our gifts are, and serve Him with all our hearts!}