People need to hear that they are doing well, and the recognition needs to be specific.

Probably the most important way to be mindful in your recognition is to start recognizing others - be present, pay attention, tell people when they are doing well.

If you don't provide feedback, the natural tendency of the mind is to assume the worst, see Negativity Bias.

How else can you be mindful?

1. Be specific. When you are specific you are engaged with that person and clearly present and speaking honestly about what you value in them.
2. Provide feedback quickly. Don't wait, do it in the present moment.
3. Recognition of small, but valuable contributions is important.
4. Consistent, frequent recognition is important - best to develop the habit of recognition.
5. Have a baseline of honest dialog with the person. If you have previously given them constructive criticism then the recognition will be more powerful and more easily accepted.
6. Recognize others to a broader audience - this may mean including YOUR superiors on the recognition email or it may mean sending a thank you note home so that a spouse or child could see it.

Number 5 is interesting and requires real ground work ahead of time. It doesn't always have to be criticism - it could be goal setting or something similar. You need an honest framework for conversations and something more than just 'you always do great at everything you do.' Sooner or later that is going to become hollow feedback.