(A big sister's advice with contributions from missionaries in her MTC district)
1) Learn how to receive answers to prayer.
2) Go to the temple as often as you can, and at least once a week after receiving you endowment.
3) Be obedient to commandments and Stake President and FSOY.
(Media, language, keep your mind clean).
4) Read JESUS THE CHRIST and TRUE TO THE FAITH.
5) Be smart, study hard, enjoy high school, be an example and always follow the example of Christ.
SOME GREAT SCRIPTURES (for missionaries):
~ D&C 4 of course
~ D&C 6
~ Alma 17: 2-3, 5 8-12 This has many similarities to our first week at the MTC
~ Alma 18: 14-23 -Similar to teaching an investigator
~ 2 Nephi 31 About the doctrine of Christ.