Let me recommend you what I have been recommending all along for the requirements of this kind. Please write the appreciation letter on your own and upload on this forum. Some senior like me will correct it. Just in the recent past there was similar request. On my recommendation the poster tried on her own and later improvisation was done. Refer that post:
In fact your post also has few mistakes. If you wish to know then I will show where you need improvement. To avoid these mistakes, I recommend you writing the posts on MS Word and then copying and pasting them on this forum.
Dinesh V Divekar
We keep receiving such requests for serving everything on a platter.
Such short-cuts are akin to copying someone's homework as school children do; however it does not result in any learning.
As rightly advised, one should make a genuine and honest attempt and put up a self-made draft first.
Please do not feel embarrassed or worried of any ridicule, even if the draft is not proper. Rather than being foolish or handicapped through out one's career; It is better to appear foolish one day and become wise for the rest of your life.
Please be Professional.
What was the nature of work
What he had done
What were the stapes he had taken to complete the work
How he faced the obstacles during the job
How much time he had taken to complete the work
How much relaxation he had given to your Organisation
All the above are require to give a Professional Appreciation Letter, Otherwise there will not be any value of giving such. So by giving priorities to the above points you can draft a good Appreciation Letter by using some decent Professional words.