Simply replace the unfilled areas such as "" and "[date]" with your information.
It is with pleasure that I recommend [First/Last name] as a true professional. I have worked with [Mr./Mrs.] [First/Last name] on numerous occasions through [organization/graduate school/college/etc] and have found [him/her] to be an exceptionally professional individual. [First/Last name's] ability is phenomenally strong and i asked [him/her] to take over the care of my [client's/patient's] needs whenever I simply couldn't because of personal difficulties or simply when i had just to much work on my shoulders.
We worked on several projects together and I have always admired [name's] professional judgment and experience when it came to take care of my [clients/patients].
Without a doubt, I would recommend [first name] to any organization. [He/She] would be a great asset to any team. [He/She] is a very competent individual with [#] of years experience behind [him/her]. I am confident that any organization will find [name] to be very knowledgeable and a pleasure to work with.