I have just entered another competition, this time on the Writelink website. My story is called "Secret Santa", and I wrote it after sitting with my laptop on my knee, and challenging myself to write, edit and send a story off in under an hour. I think it was 45 minutes in the end. Please feel free to have a look at it, and there are some other great stories on the site too. If you're struggling to get that festive feeling, they may just help.
I constantly have thoughts in my head of the competitions I want to enter. They're all bookmarked in a folder, and I keep looking at them every now and again and wondering which one to tackle first.
It's only when I am doing something mundane that the real ideas come to me. I was ironing last night, and the best part of a story jumped into my head. I immediately stopped ironing and opened up my laptop. Previous ideas have come to me during showers, and when driving up the road (away from the house, naturally).
If you are struggling for plot ideas, perhaps it is time to think about doing something completely different; go for a walk or do something totally unrelated to writing. You never know what may happen.