Use a person you admire as an ideal for yourself
What would they do?
Take a person that you admire and use them as an ideal for yourself.
Carry their thoughts and ideas around with you. Remember their face, their voice, their thoughts, their actions.
When in doubt, ask yourself - what would they do?
What would Marcus Aurelius do? How would he think? How would he act?
You will feel embarrassed to go against the ideals of your ideal.
It will be obvious you are not on the correct path.