I don't know of a secret. Perhaps there are ways to cheat, but don't know about that.
There are some tasks that are specific to certain area. From what discussion I have seen elsewhere, it appears for example that the US users get tasks that we don't see. I noticed US users on Thursday making a big march up the top 10 list. I believe that day they had a task that we did not see. I have seen comment on the ClixSense forum from users in other countries (India for example) of tasks they had a big bunch of that were not on the list of Canadians.
I have also noticed that CrowdFlower often seems to release a bunch of task at around the same time as Canadian casinos. The US is not doing casinos at that time and can perhaps do a better job at getting those and then getting their casinos about 1 hour later. Our casinos are at about 4pm Pacific. This is getting near the end of the work day in California and might explain why suddenly a bunch of relevance/sentiment task are released that they have been preparing for release.
Perhaps never leaving the computer and checking for any additions to the list very frequently?