If you write it down, we're going to judge it.
Not just the words, we're going to judge you even before we read the words. The typography you use, whether it's a handwritten note or a glossy brochure, sends a message.
Some typefaces are judged in a similar way by most people you're addressing (Times Roman in a Word document or Helvetica on a street sign or Myriad Pro on a website) but even when you choose something as simple as a typeface, be prepared for people to misunderstand you.
If you send me a flyer with dated, cheesy or overused type, it's like showing up in a leisure suit for a first date. If your website looks like Geocities or some scammy info marketer, I won't even stay long enough to read it.
Like a wardrobe, I think a few simple guidelines can save amateurs like us a lot of time:
1. Invest some time and money up front to come up with a house style that actually looks the way you want it to, one that tells the story you want to tell. Hire a designer, put in some effort. A headline font, a body font, one or two extras. That's your outfit, just like the four suits you rotate through your closet.
2. "What does this remind you of?" No need to be a pioneer (unless that's the story you want me remember). Find a combination of typefaces that remind your chosen audience of the sort of organization you want to remind them of. Hint: italic wedding invitation fonts in the body of your email remind me of nothing except other people who have wasted my time…
3. Be consistent. Don't change it when you get bored. Don't change it when your staff gets bored. Change it when the accountant and marketing guys tell you it's not working any longer.