Create your own personal dictionary, including shortcuts for each word. So your keyboard not only auto-corrects, but knows exactly what you want to say as you type in shorthand. Follow the following steps to get going.
1. Go to Settings
2. Scroll down and tap on General
3. Scroll down and tap on Keyboard
4. Tap on Add New Shortcut
From here, you can add new phrases and assign optional shortcuts to them.