The following is from page 73 of the February Ensign magazine.

1. Learn together. During family scripture time and everyday teaching moments, discover the gospel together.
2. Pray together. As you call on Heavenly Father, you will find that He loves each of you.
3. Hold family home evening. Set aside a time each week when you can count on being together.
4. Make wise media choices. Ensure that what enters your home is edifying.
5. Serve side by side. Grow closer together through service, such as helping a neighbor, sharing the gospel, or doing family history.
6. Express love daily. In word and deed, show Christlike kindness.

What are the most important things you could do to strengthen the love in your family? The six above are among the best. Find more about strengthening your family at family.lds.org.