What’s good timing for grad school? For some degrees, the best timing is probably never. The benefits of the degree will never outweigh the problems it creates. For some degrees, going fast is key, for others, taking your time can ward off common missteps. Here’s a primer on how to approach a looming graduate application:

Timing for an MBA: Fast
The value of an MBA goes down the longer you wait to get it. At the beginning of your career you can get a jump-start out of the gate with an MBA from a top school. Midcareer, you won’t get that jump-start, because you’ve already started. So at that point, the MBA is just a ticket to play; most large companies like to see an MBA before moving you to the top levels of management.

It used to be that business schools encouraged candidates to wait a few years before applying. But that timeline doesn’t make sense for women who want kids. Today, most young women who want kids want to have them before they’re 35. So if you wait three years to go to business school, and then get a job afterward, you will have very little time to work before you start having kids. And then many benefits of the graduate degree are lost.

In an effort to encourage women to apply to business school, admissions departments are becoming more willing to take candidates straight out of college. For young women, this is a very good option.

But only if you’re sure you need that degree. If you don’t know what you want to do with the MBA, then you probably don’t need it. For people with no clear plan after business school, the burden of school loans to pay for the degree is often more limiting than the number of doors the degree opens.

Timing for other professional degrees: Slow
The cost of going to graduate school when you have no clear plan for afterward is even higher outside of business school. If you get a job in, say, public policy, and then decide you don’t want to go into that field, that degree makes you look unfocused, at best. You might think that more degrees are just more qualifications, but in fact, when you spend years getting a degree in a field where there are no jobs that interest you, you put a red flag up to employers that either you don’t know what you want or you don’t want them.

If possible, you would do best to leave frivolous graduate degrees off your resume so you can look a bit more focused.

Take time to work in the field you’re considering, to make sure that’s what you want to do. Have patience with yourself to learn a bit about who you are. It’s nearly impossible to make a decision as a student about what you’d want to do when you’re not a student. That’s the value of taking time to work in between college and grad school.

Timing for an advanced degree in humanities: Never
Baby boomers have a lock on tenure-track teaching jobs, and those boomers aren’t going anywhere any time soon. My favorite statistic in the world is that you would have a better chance surviving the Titanic than getting a tenure track job in the humanities. Members of the Modern Language Association routinely discuss this problem at the annual meeting, and in trade publications.

So look, if you love French, take a long vacation in Tunisia. And if you love Dante, read him at night, after work. You don’t need a degree in the humanities to enjoy learning.

Timing for law school: Try marketing first
Did you get a great LSAT score? You know what that means? You’ll do a great job in law school. Unfortunately, that is no indicator of how well you’ll do in the real world.

In a law firm, there is no clear partner track anymore. You can be de-equitized at any time. And the determining factor for your worth is not how well you analyze a case, but how well you drum up business. Lawyers are part of the service industry, and service professionals differentiate themselves through marketing. So you’d better be great at marketing if you’re going to law school.

Thinking that you’ll do nonprofit law instead? Then you need rich parents or a rich spouse because someone’s gotta pay off those school loans and it’s not going to be the ACLU.

The bottom line for grad school? Try new things, meet lots of different people and use these experiences to help figure out what to do. Take time to get to know yourself, in the post-school world, in the work world.

You need to know who you are and what you want before you start signing those school loan papers. A degree only helps you if it’s getting you to a place you really want to go to.