Your first consideration is always going to be message-to-market match.
That means you'll want your logo's colors, typefaces and any imagery to look as if it belongs on your products and in your business - and appeal to your audience.
But logos need to be simple.
If your logo still communicates when it's printed in black and white, as small as a half-inch square, that's a good logo.
Because you'll know you can use it on anything - even pens and golf tees. And it'll definitely work on your web site, even from a phone.
And you know it will also work as a full-color, room-sized banner at a conference.