You’ve been thinking about changing careers? Or evolving your career? You’ve decided to join the glamorous ranks of the rich and famous, all-hallowed User Interface designers.

Oh boy buddy have I got some advice for you! Here are 13 things you’ll need to know to be successful:

1. Be prepared: Everyone, and their cousin and their dog thinks they can do user interface design.  
   UI design looks easy.  It looks like art and common sense.  And honestly, that’s one small part of it.  However, because it looks easy, everyone you will ever work with will think they can do it better than you.  It’s ok.  Let them try, because sometimes non-designers come up with really neat ideas just because they don’t know what they’re doing.
2. None of your perfect first-draft designs will ever go live. 
   Being a UI designer means balancing the needs of the user and the needs of the business.  If you’re lucky, you work in a company where this isn’t a big conflict.  But unless you are a one-person company, your designs will need to change to accomodate other peoples’ tastes and needs.  Don’t take this personally.
3. Some of your designs will totally and royally fail.
   Be glad when this happens.  You aren’t a real designer until you have had a colossal failure.  Seriously.  I won’t hire someone who hasn’t failed.  The lessons it teaches you sting like hell but it makes you so much better.
4. Pay attention to the small details.
   Every detail is important.  Every pixel counts.  Pay attention to dimensions, fonts, letter spacing, shadow directions – everything.  Look at every bit of every design with a critical eye because each iteration will be subconsciously used to measure your skill and worth to the company.
5. Do one project, for a non-profit, for free.
   A lot of people out there will jump up and down and tear their hair out when they read this.  There’s a big stink in the creative community about “don’t work for free”.  I say that’s BS.  Pick a non-profit or charity.  Do some design work for them for free.  This gives you a chance to fill out your portfolio, lets you meet really nice people who can recommend you later (and will) and does some good for the world.  Everyone should volunteer.  Don’t listen to the grumpybutts who say you’re devaluing their work by doing yours for free.  One project won’t crash the economy.
6. Be ready to explain every decision you make.
   You’ll be asked why you made something blue.  Why it’s on the right. Why it’s round.  Have a reason.  Don’t ever make arbitrary decisions.  It’s ok if, occasionally, you say “I can’t really explain it, but it just felt more aesthetically pleasing” – every once in a while.  But MOST of the time, you need to have a valid, logical reason.
7. Ask yourself WHY often.
   When you finish a design, ask yourself why you made every decision you made.  Why did you make that font blue?  Why is that all caps?  Don’t be afraid to say “I don’t know” to yourself, but then don’t be afraid to make changes as a result.  If you can’t justify a decision to yourself, it’s not going to hold up for your stakeholders or your users.
8. Get other opinions.
   You need to become used to being a collaborator.  You’re not a holy artist up on some mountain, working in isolation to create the golden idol of design.  You’re designing something for people to use, so you need to ask people what they think.  I’m not just talking about user testing – I mean ask people if they think that radio buttons are the best way to do that, or if they’ve seen something new and better.
9. Get ready to lose some battles.
   Sometimes, no matter how right you are, you will get overruled.  When this happens, you have to think: how important is this?  I ask myself how many users will be affected, and how much it will affect the user’s experience.  Is it just not ideal, or is it truly bad?  Go to the mattresses to prevent something from being bad, but consider letting not-ideal go live, and then testing into the ideal design.
10. Familiarize yourself with standards.
    Computers are confusing and complicated to a lot of people.  Make life easier for them by doing things in a standard way as often as possible.  Make life easier on yourself by using established design patterns.
11. Make yourself some PSDs and use them.
    I have PSD libraries of widgets and elements I use often.  This is everything from a sample flash message to radio buttons to a grid template for spacing.  They save me immense amounts of time and repetition.
12. Test like a fiend.
    If you’re ever not sure, test.  If you’re ever sure, test.  No matter how awesome you are, your users will show you that you don’t know as much as you thought you did.  Be humble and be prepared to let your users teach you.
13.  Don’t take things personally.
    You are not a diva.  You are not special.  You are not granted some gift that others don’t have.  Also, your designs are not YOU.  If someone doesn’t like one of your designs, it’s not because they don’t like you.  Don’t take anything personally.  When you have a bad day, go home and grouse about it, and then let it go.

There are plenty of technical skills you should learn – html, css, javascript – and tons of art concepts to grasp – color theory, composition, balance – but those are all easy to learn. These 13 pieces of advice were hard won with fifteen years of greying hair. They’ll make the difference between a passable designer, and a really great one.