1) Show yourselves to be an example to other believers. 2) Compare your relationship to only one other. 3) Avoid fleshly temptations like you would a bomb. 4) Edify each other always. 5) Always be ready to give the grace of forgiveness.
6) Seek the Lord together. Spend time nurturing each other's spiritual growth. You can do this by reading and studying the Bible together as a couple. When my wife and I were engaged we used a workbook entitled, Discovering God's Will. It was a great way for us to grow in the Lord, but also to grow closer to each other in a Christ-centered way. Also, I encourage you to make a commitment to close your courting visits in prayer. Pray for each other's needs, the Lord's protection over your purity, and for God to be glorified in your relationship. This will knit your hearts closer in union with the Lord. These simple, but hard-to-consistently-practice, disciplines will help you keep your focus on Christ as the center of your relationship.
If then you have been raised up with Christ, keep seeking the things above, where Christ is, seated at the right hand of God. Set your mind on the things above, not on the things that are on earth (Colossians 3:1-2).