Maybe that's the problem. See.... maybe you go and draw something and discharge it right away... you should go ahead and start the design. As you go along trying effects, colors and moving things around on the design, it will come up all together at one point.
Try to start with a basic idea of what you want to accomplish. Is it going to be a hosting design, a blog, a shopping cart, a clan? Then set the colors you will like to have, or at least the environment (dark, clear, metalic, sexy, etc.). A place I go to combine colors is
Color Combos Tester.
As others mentioned, try to browse some sites of the kind you are willing to design... maybe for a part of your design that you aren't sure what to put or it's just empty.
Also, very important... don't design only for YOU!!! don't only take in consideration colors you like, or "man" style. Think that women BUY in this industry as well. So pinky and flowery designs will sell as well as dirty and metallic designs.
The thing to start the design, and the creativity will come through the process.
Have fun!