So this may not be the correct way...but here's how I do it.
I decide on what I want to promote mlsp or my blog or both,
1st: I search the asa forum for a new company that has some potential and do my research and write a review light stuff but stress the importance of a sales funnel and targeted marketing. Creatively backlink maybe syndicate, first week (google first page) then disappears (4-5) weeks later top 3.
2nd: The second I'll dig here or wso for good topics and then some similarities between some twitter trend and write accordingly
3rd: You can use rackandwrite.com to come up with ideas.
I just started using this amazing little tool
Keyword Gem based on the popular long tail keyword searched terms.
I will say that if you have your name for your blog you have absolute freedom to write about anything you want and tie it in an additional income opp. Expand beyond the MLM niche Sales Is much bigger and you can build subscribers to your lists. hope it helps