I'm starting a business. (Quit my job in February, in fact.) I don't have a co-founder. Here's my cunning plan.
I build things I find interesting, and search for product ideas that other people are willing to pay for. I talk about what I do. This seems like a good way to meet and talk to the sort of people who are interested in making money by doing the sort of thing I do.
There's been a lot of talk about how not having a CF is a handicap. Let's say it is. You can get started, or not, but not getting started doesn't seem to get you closer to your goal, make you a better CF, or bring you into contact with people who can help you with your business.
It would be nice to have a good CF; a long-time acquaintance with a compatible personality, complementary skill-set, rich parents, entrepreneurial bent, few obligations, etc., but you either know someone like that or you don't. If you don't, it will take years to change that ("long-term") and it seems silly to wait, if you really want to do your own startup.
Sometimes, you have to make do with what you have.