Pick a word, any word and write about it. Open the dictionary, the first book or magazine you can put your hands on, the back of the cereal box. Pick the first word you see and write it on the top of your paper. Then wait a moment for something to come to mind and write about it. It doesn't need to be heartfelt, funny, brilliant, or even true. Make up a story or find a memory about the word or some association to it.
Perhaps the word is microphone. You could make up a story about someone testing a microphone before a big meeting and it doesn't work, then what happens? Or wonder what did people do before microphones and they had to talk to a loud crowd. Did the message get across as well? Better? Or write how cool it feels to hold a microphone. Write about how you used to pretend a brush was a microphone and you'd belt out BeeGee songs in the mirror. Or whatever. Then just keep writing and something else might spark your interest as go along. It's just to get the creative juices flowing and get away from, "Today I did this and that and I got made at so-and-so and I wish I didn't eat so much ice cream but I always do and tomorrow I'm going to do 50 situps."