I read some excellent advice on here recently from someone who earns a lot of money here. He said that it's best to write whatever excites you the most. Look through your list of possible article ideas, and go for whichever one physically gets you excited. I'm starting to steer more in that direction myself. Even though I recently said I was going to try to write whatever I thought would earn me the most money, I'm now thinking that writing what gets me most excited might be the best way forward.