Overtrading goes hand in hand with impatience.
If you don't have a setup, do not trade.
Don't makeup trades just because you have a trigger finger.
Wait for the setups you have in your trading plan, and then trade those setups without hesitation.
Overtrading can also be that you exit your positions too soon before reaching your take profit target.
"But I heard you can never go broke taking profits?"
Here's the truth:
If you don't have the patience to let your profits run according to your plan.
Then, you're not following your plan.
If you take profits early, your losses might end up larger than your profits. That's a bad risk reward ratio.
So, be patient when you are in a trade, and let your trade reach your take profit target.