Observe nature and notice what is going on in the world around you as you sit down to journal. Write about the weather, the wildlife and the trees.
Browse through the newspaper. Write about articles that interest you. Talk about your feelings while reading a particular article or opinion piece.
Dust off those old photo albums. Leaf through them and dig up old memories. Write in your journal about memories the photos elicit.
Make a journal jar. Write out as many topics as you can think of and cut the paper into strips. Drop the strips into a jar, and decorate the jar if you wish. When you are stuck for a topic, just reach into the journal jar and pull out a topic strip.
Prepare a Topic of the Day list. Number a piece of paper 1 to 31. After each number place a topic, such as names of people, money, holidays, food, work, church or quotes. Paste the list in the front of your journal. Every day you will have a different topic to write about and you can use the list over and over again.
Just put pen to paper and start writing whatever comes to mind. Close your eyes and let the words and sentences just flow. Write down everything that pops into your head, no matter how silly it seems. Very often you will find the perfect topic to write about within this seemingly chaotic flow of thoughts.