1. Write about a blog post in your niche. If you are like me, you would have subscribed to at least a dozen blogs in your niche. Do a short review on any one of the blog posts.
2. Ah, here comes the easy route. Create Google Alerts on topics of your interest, preferably in your niche. You will have your hand full of blogging ideas. This is my number one resource.
(even this very blog post is a result of reading Google alerts)
3. Some of the comments in your blog post may be worth elaborating on. You can dispute it or agree with a comment. It will be better if you throw a challenge to the commenter.
4. List posts always attract readers. Compile a big list of various resources.
5.Blog carnival is a big resource. Haven't tried it yet. You can join a blog carnival and learn what it is all about. Then, you can host one which will attract several blog posts posts.