I had a problem pushing maps to completion. I made a UT2004 map once based off the 3dbuzz tutorials. I also made a UT99 map as well without a whole lot of help - just some tinkering. The first didn't look that great, but I was proud of it from a gameplay standpoint minus a few things about it (namely some deadends), but the point was that I was experimenting. I never released either map, but I learned a lot from making them. My point is that it's not that you are uninspired, but that you need to open up an editor and just play. If you have fun doing it - mapping is for you and you will learn a lot.
Three to four years after my first foray into mapping and finding it enjoyable, I am pushing myself to actually finish a map. There are two reasons it took so long: One was that looking at my old maps and concepts for maps, I thought that I wasn't good enough and two was just a lack of time.
It's not so much that I have more time now, but that I am overcoming the first obstacle and am finding that the time is there - I just wasn't letting myself see it. So, my recommendation is to doodle on a sheet of paper. Get an idea from photos or just your imagination and commit to it. This may sound hokey, but it's working for me. Set a schedule for yourself - it pushes you to work hard on your map and then convince yourself to release it and give project updates to the community. Listen to their comments, ask for their help and commit yourself to build a map that you can share with these people who have given you their time to help you complete it.
I plan to put up the alpha release (just basic geometry) of my ctf map this weekend/early next week depending on how fast I can get a coding project done for a class. Pushing myself to sit down and commit to a general schedule has inspired me to start and complete my map. Thus far, it's worked.
Sorry for the lengthy response.