The use of font can make or break a logo. Having to many different typefaces can cause for a sense of clutter and confusion. Using 1-2 type faces in a logo can be plenty, this way everything can appear unified while having contrast. Choosing even one type face will work but make sure your not using comic sans, a poor type face could break your entire design.
Originality is another big factor. You want to be memorable, simplistic and unlike everyone else. This can be done through good graphic design and typography, what should be avoided is the use of stock images. These are accessible and convenient but will not provide you with what a quality design can. Use of color can be good or bad, being that it can add spice to your logo. What you don't want is to make your logo color dependent. Color is associated with so many things that is almost impossible to leave a lasting impression based strictly on your color choice. Simple graphic elements can solve this dilemma.
As a designer it's important to make sure that when saving/ creating logos you do so with vector images. These vector images are made of precise points which allow for multiple sizing options and transparency. Where as using a raster graphic only allows for sizes saved as, this is because these images are made up of pixels that when stretched don't correspond.
Lastly if designing a logo, don't design the logo for you. Designing for others can be hard but once masted can ensure a great source of income and reputation.
Source:
http://www.smashingmagazine.com/2009/06/25/10-common-mistakes-in-logo-design/
