Many Jewish sources suggest that good themes for bat mitzvah speeches relate to the weekly Torah portion, or parasha. While many Torah portions have either legalistic, archaic or age-inappropriate themes, there are many resources available for finding the modern meanings or broader themes of these portions.
Whether speeches are being made by the child attaining their bat mitzvah or by friends or relatives of the bat mitzvah, a common method for writing these speeches is to combine Torah portion themes with personal connections. The Bureau of Jewish Education suggests finding a symbol or analogy from the Torah portion that relates to one's personality, family history or hobbies. Similarly, the Jewish Journal advises speakers to connect themes from the Torah portion to important childhood memories as a metaphor for growing into an adult.
There are also many common bat mitzvah speech ideas that are unrelated to the weekly Torah portion. Chabad advises addressing how the speaker shows their growing commitment to Judaism. Some bat mitzvahs speak about Jewish values and traditions that are meaningful to them, or about memorable Jewish events that they have celebrated. Many bat mitzvah speeches describe the process of training and practicing for the big day. Finally, almost all bat mitzvah speeches conclude by thanking all of the people who have supported the speaker and helped them to make it to that moment.