Logo should be simple yet unique.
Logo should be able to work on both white or black background
Logo should be simple enough to work as a vector image. (It should work in black and white - logo loses NO meaning when you remove the color.) Logo should be possible to laser engrave on a product like:
Avoid creating a logo where the aspect ratio is really wide and very short. A text only logo where "NEON NIGHTLIFE" is written out on one a single line would likely be too long and not tall enough for many applications. The aspect ratio is a logo’s relationship between its height and its width. Bottom line, you don’t want a logo that’s too tall or too wide. Squarish is always best, as this allows the maximum adaptability of a logo.
Some logos are too complicated and it makes the company name not prominent in the design. An example is the Starbucks round logo. I can't read the company name from far away. Good designs where the logo is mainly just the company name is: CocaCola, Oreo, Puma, Lowes, Dell, Nintendo, Subway.
IT SHOULD MEAN SOMETHING.
Generally, there are design elements in the text or a design symbol that sits next to the text. The design elements should connect your potential customer to what you do. This one is pretty obvious but it really does help. If you have a mortgage company it might seam cliche to have a house but if you can be clever and figure out a way to incorporate a house in it that would be great.