probably you are too ambitious for your ideas ... just try to build the first thing that came to your mind ... doesn't matter if it already exists or if it seems silly at first sight.

for example a website to gather ideas for side-projects :)

my last two side-projects aren't not very special or solves any problems ... but i learned much just doing it ...

http://bohuco.net/blog/2013/02/my-january-sideprojects-what-...