I go out and shoot sunrise/sunset on many weekends. Ill take 20-30 shots during the 30 minutes where the light is the best and Ill end up with 1-3 images that actually make it to my website. Then, 3 months later Ill look at my galleries and realize I should have cut out another 30%.
Checked out your flickr, I had some observations - you can ask me to remove them if you'd prefer but I'm really just trying to be helpful, not critical.
It looks like you live in a photogenic area and you have an eye to recognize WHEN a scene is worth shooting. Your images also seem TECHNICALLY sound, meaning you know how to use the camera and accessories for shooting landscapes (DOF, sharpness, etc).
I think what might hold you back is the amount of thought you put into your shots. It seems like you find a scene that makes you go "wow, that would be a great picture!", then you rush to set up your tripod and end up taking a shot at eye level without much interest in your foreground or maybe there's a street lamp or shopping mall in the distance. Then, when you get home you just dont have the same feeling looking at it on the monitor that you did when you were there.
A little bit of planning would take you a LONG way. Find a spot thats WORTH photographing and isnt marred by signs of development, go there 30 minutes early and set up a shot that isnt relying on a striking sky to carry the image. That beautiful sky should be the icing on the cake, not the only thing worth seeing.