Ahh this is horrible, I don't know where to begin. I am completely stuck; there are basically 6 or 7 groups to discuss which can be roughly split into effective and ineffective.
I don't know whether to organise it chronologically, explaining what and why for each and then tying them together, or thematically, ie tying them together by reasons for the success, but this seems to be drifting from the essay title a little:
"How effectively did Irish Catholic and nationalist leaders advance their cause in the years 1801 - 1921"
as it would be assessing why they were effective rather than how effectively...
I really want to make this piece my best, but I've never been this utterly stuck before! Could anyone offer any advice?