Note: I say "ideas," not "good ideas."
But even with that caveat, I feel like my training in creative and non-fiction writing gives me a perspective on idea-generation that could get me some annoyed looks. So, to be clear:
When I say "ideas are cheap," I don't mean, "Ideas are cheap for me, I have a million ideas, they just come to me like a friendly bird":
I mean "ideas are cheap for everyone."
Sure, some people have blocks or difficulties--like the block where they tell themselves that they are not all that creative.*
But really, if you don't self-sabotage by telling yourself that you have no ideas, I'm sure everyone can come up with a bunch of ideas. (Remember: I'm not saying these ideas are good.)
You could start with thinking about your day: what would make any area of your day a little better? What would help anyone you know?
Now branch out from there into things you're interested in: What would someone you know really enjoy? What's something that's cool? What's something that I'm passionate about?
Think also about the techniques and tools you might use: What's something that's challenging? [Note: this is an especially great question for creative writing.] What's something that's almost inside my comfort zone but not quite? What's something that I can do to show off a little?
Take a lesson from Tina Fey and her book Bossypants (or better yet, take a lesson from the improv classes that you took--because everyone should take improv classes): at this stage, just write down the ideas, without judging them.
See? Ideas are cheap.