A Good Concept
The purpose of a logo is to identify a company, not to tell its whole story or showcase its catalogue of products and services.
What is the core idea or emotion your customers should associate with your business? Is it relevant enough? Is it the reason why your customers choose you over your closest competitor?
Once you’ve identified that central concept then you can begin to make every little yet crucial choice within the process of designing a logo.
Simplicity
If you have a good concept (i.e., a clear idea of what makes your company stand out), then it will be easier to come up with a logo the is as simple as possible.
Why do you want a simple logo? Because it is easier to identify and remember. Users are permanently saturated with content so you should think of your logo as a catchy tune you want to stick in your customers’ heads.
Memorability
Your company is meant to grow and evolve into something different. Many things will be constantly changing (your website, your ads, perhaps your stationery) but your logo should remain a solid constant. This way your audience is always able to identify your organization when browsing for the solutions you offer.
Geometric Soundness
Should your logo be beautiful? Yes, but who gets to judge? To make sure your logo is visually attractive and easy to understand for your target market, it should adhere to the basic principles of balance, contrast, modulation and following a gridded layout.
A good way to test geometric soundness is to scale your logo to the smallest and largest possible sizes. If it’s still readable then you’re good to go.
Just remember that balance doesn’t always mean symmetry and a grid shouldn’t constrict your logo into a boring, bland design. Your logo should always stand out!
As Few Colors as Possible
Three at most. And they should derive from the logo concept (e.g. orange for a dynamic company or blue for a firm offering security above all). DON’T CHOOSE A COLOR FOR YOUR LOGO JUST BECAUSE IT’S YOUR FAVORITE.
BONUS: A Black and White, Grayscale and White Version
You won’t always be able to use the full-color version of your logo so make sure you have the proper alternate versions to use against dark backdrops or single color prints, engravings or stamping.