Send some over to me haha
I know that this is a problem for many new webmasters because at first we have a concept and idea that's great, but the execution doesn't live up to that and we don't get what we intended, such as big hits and audience. Then suddlenly the enthusiasm for that site dissappears and we move on to the next big thing, but it just suffers the same fate.
So my advice is:
1) When thinking up concepts, buying domains, making the website, think that is it really worth it? Does the site you want to create have something unique?
2) Be Sure to have a firm idea on how you will create that website. Such as will you use a free script or what, and make sure to check it fits your budget and time.
3) Be Sure to have an idea how you will market/get your website known! Too many times we create good concepts but fail at the marketing. Have a good plan for marketing, as marketing is a LOT more important than anything else.
So basically, have a rough but good plan on what you'll do, so when it comes to doing it you know your stuff. Don't have an excessive plan, a brief note like plan is better. It also depends on what type of site you're making, but you may want to make some notes on future revenue streams for the site.
Also, if you have incomplete websites/domains, sell them off? If you have any decent domains, here are some good places to sell:
http://www.sedo.co.uk/
http://forums.digitalpoint.com/
http://www.dnforum.com/