(From http://www.statementofpurpose.com/recos.html )

What are recommendations for ?

Recommendations are meant to provide a third-person perspective on you as an individual. While your grades/scores are supposed to represent your intellectual capabilities and your essay allows you the opportunity of presenting your point of view, recommendations by those who know you give the university an independent assessment of your skills and qualities.

Unfortunately, a number of applications ask for elaborate recommendations that are frequently a burden on faculty and superiors. It's not uncommon to hear of faculty asking the student to write his/her own recommendation and then editing them for effect. This is even more likely to be the case in a work environment, where few would like to waste their time answering often absurd questions. 

In response to requests from visitors to our site, we've decided to provide some advice on how to make the most of your recommendations.

Here's what we, ..uh, recommend...

Please note that by no means do we endorse the practice of applicants writing their own recommendations. It put many students in a position they'd rather not be in. But the sad fact is that many applicants have little say in this matter. 

And even if you are fortunate enough to have people around you who are prepared to write up their own recommendations for you, there are certain aspects you could try to keep in mind. Hence this section should be useful for all applicants.

How to go about doing it

Make a list of persons you are going to ask to recommend you.
If possible, jot down a few extra names whom you could depend on in case of an emergency.

Make sure they are willing to do so.
Talk it over with them. See if they are reasonably sure they'd like to do for you. Be clear that recommendations are a pain for everyone involved, but most so for those who have to actually write them up. No one enjoys writing recommendations. And so you can't depend on someone who isn't too sure he/she'd like to recommend you.

Make sure they know what you want to do
If they knew you were interested in marketing research and not finance, maybe they wouldn't have said that you'd be a great asset to the finance class. Of course, the persons recommending you are often busy people, so you may want to give them a note alongside the rest of the material we've listed in our next point.

Each of the persons recommending you deserves a copy of your resume. Along with that, give them the original recommendation form and a copy too. In this copy, give them points that you'd like covered in their write-up. If the form asks them to list an incident where you displayed leadership skills, it'd make it easier for them if you have provided them with a few incidents that you think would be suitable. Let them do the descriptive part. Your job is to make sure they remember a few relevant incidents. You could even attach a note saying that you'd rather they talk about your pet project, etc.

Related Issues
Make your timeframe absolutely clear. And while we're on the topic, be considerate and give them a few weeks to prepare your recommendation. Be sure that you've given yourself a buffer of a week or two to make up for unexpected exigencies. Also clear up whether they'd like to mail the recommendation themselves or whether they want you to do the needful. Consult the application brochure to make sure you're aware of what your university prefers.

Selecting the right people to recommend you :

Do they know you well enough
You don't want to go for someone who doesn't remember your name. Which is why it's always prudent to stick with immediate superiors or professors (in an academic setting). More importantly, will the university believe that they know you well enough. If the CEO of the firm where you interned is recommending you, make sure it's clear that your interaction with the recommender is apparent in the write-up. The University could very well question the credibility of a recommendation if it appears to have been manipulated.

How much credibility are they likely to hold with the university.
In academia, professors are likely to carry more weight compared to lab-assistants. In any case, make sure that the professional competence of the person recommending you is apparent.

Are they likely to give you a positive recommendation
And you want to be doubly sure of this. You may want to stay away from the unreliable ones. If necessary, approach the person and ask them upfront. Since they're likely to have written recommendations for applicants before, it's not too much to expect them to understand your anxiety. However, use your discretion in case you aren't too sure of how he/she will react.

Get some variety into your recommendations
For multiple recommendations, look out for whether the recommendations are likely to rehash the same aspects of your personality. As far as possible, get recommendations from people who've interacted with you in different situations. For example, an engineering student would be well advised to get recommendations from a professor, a lab instructor and someone like a project guide. The professor could attest to the student's keen sense of class participation. The instructor could focus on his/her skills in the laboratory and the project-guide on his/her flair for research and getting to the root of problems.

Co-ordinate your recommendations with the rest of your application
If the somewhere in rest of your application you've focussed on something like a particular project, it would be particularly useful to try and build on that by providing a recommendation from the person who guided you through that project. Likewise, if you've talked about your biggest achievement at work, how about getting your boss at the time to recommend you.

If you are writing the recommendation yourself

Make them sound different
Writing all your recommendations in the same style is just asking for trouble. Remember that these recommendations will stay on your record for a long time to come. So even if you aren't caught during the application phase, it's quite possible that they'll come to haunt you, say, when you're begging for an assistantship.

Don't use too many superlatives.
None, if possible. And never in pairs. Saying that you're the 'most brilliant' student to have walked the halls of the college is poor English and likely to result in that recommendation getting excluded if your transcripts don't back it up.

Make it believable
There's no doubt that you're the brightest student your professor has ever seen (like the dozen others who have asked him to recommend them). But if your professor puts you in the top 5% in every category that he's been asked to rank you, and your transcripts show that you averaged in the bottom 25% of your class, it's bound to raise some eyebrows. So take it easy on those adjectives and percentages. Make sure you match up the assessments in the recommendation with the hard figures that your transcripts reveal.

Try and talk about aspects of your personality that haven't been covered elsewhere
The recommendation really is a magnificent opportunity to do this. So instead of getting your professor to describe your entire project (which you've already talked about in your resume/essay), say that he saw you grow during the year that you were assisting him on the project. How your already superior fundamentals in the subject were reinforced by your having developed considerable finesse and accuracy in the laboratory.

Refer to the essay writing part of this site
Think of it like an essay. In fact, it is an essay. So for god's sake, give it structure and flow; and work on that content.

Try to get across outstanding achievements
Read your resume and essay again. See if this recommendation provides you with a chance to bolster some of the claims you've made elsewhere.

Co-ordinate with your goals
Think of what you'd like to be doing in the near future. For example, science and engineering students generally seek assistantships in research or teaching once they're at their university. It's quite likely that the person reviewing your application for an assistantship will look at your application recommendations. If someone recommending you has said something about your having presented a seminar on 'Big dams are examples of poor engineering', or having conducted outstanding research as part of your project, it would substantially add to your chances of clinching the assistantship.

Use discretion and good judgement
Since you're depending on others for this part of the application, your staying sensible is of utmost importance. Everything from scheduling meetings with the person recommending, to giving them a deadline, to suggesting what they should highlight in their assessment requires a lot of tact on your behalf.