Headshots are generally above the waist.  So you really only need to consider your shirt or blouse.  

Solid colours are best (least distracting).  Subtle patterns or stripes can be ok.  But busy patterns, prints or words will detract from the overall objective... which is to see you.  

It's important to feel authentic and confident.  Wearing clothes that amplify your confidence can be super helpful.  However, sometimes our favourite clothes that look amazing in real life don't always look ideal on camera, under the lights.

Ultimately, the best plan is to bring some options.  Just 2 or 3 different shirts, 1 or 2 ties...  A jacket or two.

If it's a full length shot, you need to make sure the shoes, belt and other accessories are right for the look you want.  Ladies generally photograph better in heels.

Jewellery should also fit the look and not distract.  

The best thing you can do is bring options.

PRO TIP:  DON'T WEAR THE Shirt YOU PLAN TO WEAR IN YOUR PHOTO... BRING IT WITH YOU AND CHANGE JUST BEFORE.  THAT WAY IT STAYS FRESH AND UNWRINKLED.