If you think of B-school applications as a trial, your recommendations are the part where you call witnesses to testify. And every lawyer knows that an unreliable witness can sink a whole trial.

Letters of recommendation are no different. Lining up recommendations that reinforce your personal brand is essential. Here are 5 mistakes to avoid making with your B-school recommendations.

– Choosing title over substance

 Of course it’s nice to have a letter of recommendation from a CEO, managing director or partner, but what’s much more important is that the letter is written by someone who has seen first-hand the value you provide.

Choosing a recommender with an impressive title who doesn’t have a direct relationship with you is a missed opportunity. Letters written by these people tend to lack details, and a letter without details is basically worthless.

On the other hand, a letter from your direct supervisor or anyone you’ve worked with more extensively will be able to back up its claims with specific examples, which will help your application stand out.

– Assuming someone is invested in you

Before asking someone to write a recommendation for you, pause and take a sober look at what that person has said about you in the past and what concrete feedback they’ve given you. It’s easy to overestimate how much value you’ve provided for someone you’re asking to be a recommender.

You want to make sure you’re asking someone who’s invested in you and who cares about your future. In other words, someone who will take the time to pen a stellar letter on your behalf.

– Approaching recommenders too late

 I sometimes see applicants trying to line up letters at the last minute. Sometimes it’s because a recommender fell through, sometimes it’s because the applicant didn’t decide to apply to business school until late in the game.

Whatever the reason, leaving a recommender with only a couple weeks to write your letter can derail your entire application. You want to give them two months or more.

– Leaving recommenders to their own devices

 Even recommenders who have written letters before don’t necessarily know how you’re going to position yourself in your application. Set up a time to talk with your recommenders in person, or by phone if you’re not in the same location.

You want to give them an idea of why you’re applying to business school and what you hope to get out of it. More importantly, though, this is a time to brainstorm examples that highlight what your contributions have been and what your impact has been at the firm (or wherever you know them from).

The goal is for your recommenders to become your brand champions. If they know how you’re selling yourself in your application, that will help them craft letters that reinforce your personal brand.

– Not building a leadership track record

It goes without saying that business schools are looking for leaders. Your leadership track record is the foundation that your letters of recommendation stand on.

If you haven’t been at a firm long enough to establish this track record, or if you haven’t taken up opportunities to create an impact at your firm in the past, you want to really evaluate whether this is the right time to apply to B-school. Waiting might be to your advantage.

Choosing the right recommenders and personal branding strategy won’t do much without a record of concrete experiences you can point to. That track record is the substance that makes the rest of your application work.

As you can see, there’s a process to go through in lining up recommendations.

First you have to have a record of leadership for your recommenders to write about. Then you have to find recommenders who know about that record and are invested in writing about it.

Finally, you have to communicate with your recommenders once you have them in place. Do those things, and you’ll end up with letters that strengthen your personal branding strategy and give you the best chance to get into your dream school.