I'm not in the habit of~

I used the pattern " I am not in the habit of ~"

1. I'm not in the habit of eating(having) breakfast. <-- Both "eating" and "having" are correct.

2. I'm not in the habit of getting up early.

3. I'm not in the habit of giving a birthday present to somebody.

4. I'm not in the habit of thinking postively. OR. I'm not in the habit of thinking positive things will happen to me. 

5. I'm not in the habit of studying English regularly.