Possible Sunday homily topics include Jesus bringing justice and salvation, God abiding in those who recognize Jesus, and praise for God's wisdom. A selection of Sunday homily ideas is available at AssociationOfCatholicPriests.ie. Each suggested homily includes Bible readings and a discussion of the themes expressed within them. The homily on baptism includes discussion of the priest's own experiences with baptism and his thoughts on its significance. The homily ends with an affirmation that God's word is powerful.
A different homily on the same website concerns honoring one's parents. After readings from Sirach, Colossians and the Gospel of Luke, the homily's discussion covers the trials that Jesus' family went through. It ends by explaining that each person must make their faith their own, and achieve full maturity by heeding the Lord's call.
When writing a homily, start with a firm topic in mind. It may be need-based, for example a discussion on finance or morality, or event-based, for example a discussion of the nature of Christmas. Various theological principles are also available as topics. Draft the sermon, ensuring that there is a strong conclusion and that the language is accessible. After editing the homily, practice it and time it. Friends and family members may be able to give good feedback.