A good way of looking at making a logo is to map out the key points:
1) The design has to be clear and concise (if there are words, it must be readable, if it's an animal you have to know what animal it is)
2) It has to reflect your brand correctly (such as gaming channels using controllers or minecraft styled characters)
3) It has to be memorable and eye catching (a very dark picture with muted colours isn't going to catch someone's eye)