Track record is also important. Look back over the years and check the company's dividend payout. Make sure it is fairly consistent through the good and bad times. A good track record gives you a better impression of the company that you will be invested in. That is why IPO stocks are such a hassle to valuate, as you may not get a concrete picture of their past perfomance.
Lastly, take note of company's debt. Make sure its net debt is small. It would be even better if its net debt is nil. As net debt would indirectly affect your dividend payout. A lower debt to equity ratio would also imply a more financially stable stock, which makes for a good candidate for passive investing.
For me, it is always preferable to choose stability and sustainability over high yields. So do look out for these basic pointers when you do cash flow investing.