How to managers to serve as coaches to employees?

Lead them by an example approach 

Train and coach them by your self as possible as you can 

The relationship of a manager and subordinate should be based on trust and commitment. These two elements are the key to the foundation of any coaching scenario. While most managers expect their subordinates to understand their expectations, in reality the path is other way round . A manager should set right examples as mentioned by Youssef above . Small things like :1) Appreciating the good work done Also emphasising on importance of doing the work correctly .2) Allow subordinate to share their thoughts, this makes subordinate feel empowered and respected by the manager which is a great feeling for any subordinate who is aspiring to perform.3) periodic sessions of performance reviews ( ex mid year , quarterly , annual) followed by guidance are good motivators and tools to excellence. Last but not the least .. Being open and allowing the colleague to be open are very important for a successful coaching scenario. Thanks,

Direct manager he explained to the staff action steps, and sometimes there will be cases differ from the daily work requires you to slice how to end the proceedings and considered this explanation as a training not only for the employee to be no more than one of these steps is the training in order in the case of future recurrence utilized How to solve this problem

And also the direct manager weekly meeting to explain the business and how to solve problems and the presentation of the problem and resolve the details of which helps the rest take advantage of some

By leading them by example:

1) do what you say

2) recognize your mistakes and correct them if possible.

to monitors his people specially if he assign to production areas and give the daily task to the supervisory of his department..

Agreed with previous answers. Thank you

By providing:

1. Mentoring.

2. Teaching.

3. Motivational counseling.

By sharing their personal life experiences, you can be a better coach.

if they sit with them on same desk 

We need to remember one thing that every manager is not a mentor, for being a mentor one must have well experience and ability to bring or transfer energy into others or sub-ordinates. Being a coach, one must guide the juniors, tactically convey them their improvement areas, bring the most from them through spotting their talent and turn them on road to success and career ladder.