1. Love your mission from day one.
Somebody told me that they regretted falling in love with their mission only six months in. They said that they wished they had done it from day one. We only get a limited time to be a full time missionary, love it from the moment you get set apart. Start loving your companion the minute you meet them. Love the people and the language the minute your feet touch the ground every morning.
2. Make mistakes as quickly as possible.
There are some who might discourage this, but the way I see it the sooner you make a mistake the sooner you can learn from it. Don't be too caught up in being perfect, people don't react to perfect. People make connections with imperfection.
3.Miracles can literally be just one step away.
There will be some days on your mission when you feel like you have talked to everyone and done everything, yet no one will listen to what you have to say. Some days when your feet hurt from walking, your mouth is dry from talking and your mind hurts from worrying. Weeks when the hand of the Lord seems missing and you feel utterly alone.
Because blessings and miracles are really just on the other side of the hill.
The days that you think you can no longer continue are the days when things turn around.
4. Don't worry about the language
The missionary is only the tool that Heavenly Father uses to find his elect. The Holy Spirit is the true teacher of the gospel. Be humble. Be genuine. Learn to the best of your ability, but don't worry about your capacity to speak the language. Heavenly Father will open the minds of his missionaries to the languages of the world.