Most people see the miracles of Jesus as something that he did to prove his divinity. He is the Son of God, so he could do all of these amazing works that no one else could do. This is indicated by the popular bumper sticker, "Next time you think you're perfect, try walking on water!" Jesus was perfect, Jesus could walk on water, you can't therefore you aren't.
But Jesus would weep at how we see his miracles. He didn't see them as signs of divinity at all. He fully expected his disciples to do miracles as well. When the 5000 were hungry he said, "YOU feed them!" When he calmed the storm, he yelled at the disciples for their lack of faith, as if they should have been able to do it themselves. He sent his apostles out to heal and even to raise the dead.
The deciding factor is this: Jesus said, "Truly, truly, I say to you, he who believes in Me, the works that I do, he will do also; and greater works than these he will do; because I go to the Father." (John 14:12)
Jesus didn't do miracles to show he was divine. He did miracles to teach others how to do them. Heck, even imperfect Peter walked on water.
1. We need the right situation. God doesn't do miracles for everyone or for every situation. But he will do a miracle when the poor are in need or when a person who was far from God begins seeking Him. God will also do a miracle when His name is on the line. The miracle is not for ourselves, but it is an extension of us loving others or loving God.
2. We need faith. Or the balls to ask (or demand) a miracle. We need to stand up and declare that the miracle will occur. And we need to have faith in Jesus. It is Jesus' power that does the miracle, not our own, and so declaring one in Jesus' name works wonders (literally).
3. We need prayer. We need to declare a miracle and ask for it. This is so we remember that it is not our power that does a miracle but God's. Any miracle that is done is God's grace alone, like a present. He doesn't have to give it, but He will, if we are gracious and give thanks.
Finally, some of the greatest works that are done are not technically "miracles" at all, but are works of community. We can feed 5000 people and more. Every day. We can heal the sick, and make the blind see and help people weather out storms and do greater works than Jesus was ever able to do, on a broader scale. All because we have Jesus' love in our hearts.
Let us never think that we cannot do Jesus' work. We must, and we will.