Simply replace the unfilled areas such as "" and "[date]" with your information.
To whom this may concern:
I've been [employee full name]'s manager at [name of company] for the past [# of months/years] [months/years]. It was my pleasure to employ [employee first name] because [he/she] consistently met and often exceeded [his/her] job requirements.
[Employee first name] was an enthusiastic, dedicated employee with a strong work ethic. [He/She] rarely needed guidance or supervision, but willingly accepted it when offered. [He/She] was consistently successful at improving [his/her] skills and worked hard to do so.
[Employee first name] was always willing to pitch in to help the team and always got the job done right the first time. [He/She] was efficient in planning projects, punctual in meeting deadlines and conscientiously adhered to company standards and guidelines.
You'd be hard pressed to find an employee more dedicated than [employee first name] and I recommend [him/her] as a rock-solid addition to your staff. If you'd like more information, I'd be happy to provide it. Please contact me if you need further details.