To create cool logos, keep in mind that the logo should represent the brand you want it to represent. It should be creative and easy to recognize. They should not look alike with any other logo in the market.
Is a very difficult and special question. Have you ever see the logo of www.pandahall.com? I like this logo, because the logo of the website is very cute and beautiful. It make me remember it for a long time. So, I hope the logo of pandahall can give you some inspiration, best wishes to you.
To design a cool logo, there are some ways to create one. Like for example; you can just grab a writing utensil and something to write on and start drawing; another way you can make a cool logo is that you can take other logos and put them together.