“For we must all appear before the judgment seat of Christ, so that each one may receive what is due for what he has done in the body, whether good or evil.” – 2Cor 5:10 ESV

“According to the grace of God given to me, like a skilled master builder I laid a foundation, and someone else is building upon it. Let each one take care how he builds upon it. (11) For no one can lay a foundation other than that which is laid, which is Jesus Christ. (12) Now if anyone builds on the foundation with gold, silver, precious stones, wood, hay, straw– (13) each one’s work will become manifest, for the Day will disclose it, because it will be revealed by fire, and the fire will test what sort of work each one has done. (14) If the work that anyone has built on the foundation survives, he will receive a reward. (15) If anyone’s work is burned up, he will suffer loss, though he himself will be saved, but only as through fire.” – 1Cor 3:10-15 ESV

There are five areas where we can gain crowns (στέφανος, stephanos):

Enduring Trials. “Blessed is the man who remains steadfast under trial, for when he has stood the test he will receive the crown of life, which God has promised to those who love him.” – James 1:12
Meeting the Needs of the Flock. “And when the chief Shepherd appears, you will receive the unfading crown of glory.” – 1Pet 5:4
Faithful Service to the Lord. “For what is our hope or joy or crown of boasting before our Lord Jesus at his coming? Is it not you?” – 1Th 2:19
Victory Over the Sinful Nature. “Every athlete exercises self-control in all things. They do it to receive a perishable wreath, but we an imperishable.” – 1Cor 9:25
Loving his Appearing. “Henceforth there is laid up for me the crown of righteousness, which the Lord, the righteous judge, will award to me on that Day, and not only to me but also to all who have loved his appearing.” – 2Tim 4:8