Calling Jesus our Lord is so common in Christianity (for obvious reasons), but do you ever really think about what that means? To be honest, it's quite difficult, because we don't really have "lords" around that we regularly submit to.
Here's a good verse, though, that illustrates what it means to have Christ as Lord:
Now who will harm you if you are eager to do what is good? But even if you do suffer for doing what is right, you are blessed. Do not fear what they fear, and do not be intimidated, but in your hearts sanctify Christ as Lord. Always be ready to make your defense to anyone who demands from you an accounting for the hope that is in you;
1 Peter 3:13-15
To me this says that it's easy to make mankind our lord, as we fear others and their opinions. But making Christ Lord means we remember that He's the one we have to give account to, and He's the one we ultimately answer to. This is a game-changer, as we can walk about in freedom, knowing we no longer need to be afraid of the opinions of others. In fact, Peter says that this is just another way to share the hope we have in Christ.
So in each action we make, there is someone we are answering to; someone driving our choices. Think about who is that person is...if that person is Jesus, then we're treating Him as Lord. If not, then start to question where that comes from.
Christ is who I have to answer to for my actions, not man.