Teacher Talking Time
TTT stands for Teacher Talking Time, and that's something you can't have too little of. What you really need is STT. After all, you already speak English most effectively so it's not you that needs to practise.
Make sure you limit the time you spend talking and maximise the time your student(s) spend talking. Talking is the one thing they can't do outside class. They can listen on their own, they can read and even write on their own. But they run a serious risk if they talk on their own.
What percentage of TTT should there be in a lesson? That's something you have to judge, depending on level, group or 121, needs etc. But, in general, you should do everything to maximise STT and minimise TTT.
Here are some activities to encourage your students to talk.