Coming off a few days interviewing in NYC, can I say, those guys know how to dress.  And I’m not talking about unlimited access to the world’s best in fashion–though who can resist a trip to Barneys?–I’m talking about common sense.

A friend of mine was in the job market recently and he sent me a hilarious note questioning what to wear in his upcoming interviews. He’s a senior, technical guy in Silicon Valley and ultimately did the right thing—guessing what the interview team might be wearing and dressing slightly better than that. He landed a great job at a great company.

What to wear during interviews, or for that matter in business in general, is an important question. I don’t like to see it cast as ‘to tie or not to tie’ as the conversation often is, because that leaves unaddressed the space where 80% of the mis-steps take place. More on that shortly.

The rules of engagement as I see it, may be simpler than you think. Technical or not, no matter what your gender, if the role requires face time with customers or is outbound facing in general, wear a jacket and slacks. Guys, error on the side of a tie. Lose the three piece suit look. Gals, error on the side of conservative. Never wear a skirt. Everybody:  wear great shoes.

If the job is inbound facing, your best bet is business casual, jacket, trousers, pressed shirt.

The more outstanding your technical chops and the more inward facing, the more you can get away with casual attire and, ‘personalization’ in Silicon Valley. And only in Silicon Valley or LA. Recently, I had a candidate wear shorts to an interview. Like my ‘Brown’ delivery guy, he apparently wears shorts every day. My view on that is, be yourself. Just keep in mind that you may be limiting your options. Life is all about choices.

But here’s the deal– 80% of the fashion disasters are in the details of choices made and ability to execute. Next time you are getting a haircut, take a look at the back page of Glamour Magazine. You don’t want to show up in the ‘dos and don’ts page’. And yes, we have seen it all on interviews—from tie dyed jeans to capri pants, everything from sky high stilettos to clogs better suited for the garden than the office. Think you could get by without getting a haircut? Think again. Think we didn’t notice you desperately needed a fresh polish? Think again.

Every professional should be intimately familiar with the iron and the dry cleaner. My guy in shorts? They were nicely pressed.