@mancunianrose, if you enjoy and would like to recommend an eclectic mix, then do that! The focused ideas are aimed at those whose blogs have a particular focus, to show the ways a roundup can fit in -- it's all about what you're comfortable posting.
@cindycpchanging, if you're not using your blog fora business/focused project/portfolio, a custom domain is less necessary; there are lots of great sites that have the .wordpress.com address. That being said, it does add a more polished feeling to your blog, and many folks like completely personalizing their corner of the internet that way; I do, so i use custom domains on my personal blogs. It depends on what you're comfortable with, what you want to do with your blog, and, of course, your budget.