How You'll Use Your Notebook
You should always have your notebook with you. When an idea hits you, write it down. If you hear a funny word or phrase, write it down. Anything you find funny or interesting should go into your notes.
The key is to write down your ideas without judging them. That's a task for a later date. If you try to brainstorm an idea on the spot, you probably won't get very far. You might just get frustrated and reject the idea entirely, and it won't make it into the notebook. And if that's the case, you've wasted a potentially great idea.
Everything in your notebook doesn't have to be in writing. Feel free to sketch, doodle, tape in news clippings, or whatever suits your style. Do anything you need to do to make it work for you.
When you have some free time, sit down with your notebook and flip through it in no particular order. Look for ideas that strike you as being funny. You can even do this while watching TV; it doesn't always need to be an active process. You just want to refresh your memory with the things you have written down to see if anything clicks.
If one idea spawns another (and it will), jot it down. You don't have to stick to your original premise. Expand on those ideas and soon you'll have one that works. You might even notice that a really great idea is actually a combination of two ideas separated by a few pages in your notebook.
Keep track of your notebook and don't lose it! If you do, you'll lose a lot of work and ideas that might never come to you again. Make sure that your contact information is visible so that if you do lose it, at least there's a chance you'll get it back. If you don't think a notebook is all that important, just wait until you lose one.
In high school or college you might have had to read aloud in class from your notebook or journal, or maybe you even had to turn it into the teacher for a grade. What a way to stifle creativity! Your notebook is for you, no one else. Don't let others look at it or you'll always be judging ideas before you write them down. You don't want people to think that you're weird, do you? (Well, maybe you do and that's why you got into comedy.)
Your ideas should be private and you shouldn't have to explain them to anyone. The notebook is just a place to empty your brain on paper. What you think is nobody's business but your own.

