Sometimes you think the subject for an essay is going to be comparatively easy! I have just finished my latest on the 'Development of Field Artillery Tactics in World War Two' (hence no postings for a while). The first problem was the distinct lack of secondary material, there are only really three authors on the subject, Pemberton, Bailey and Bidwell. The later writing three different books on the subject. The second problem, the sheer enormity of the subject, keeping it below 4,000 words - a challenge on its own. The final problem was, as I found whilst researching it, that the tactics were mostly developed during WW1 and only refined through better C3, consequently half the essay is about WW1 tactics.
I am now starting my next essay on the Soldiers Experience on the Gustav Line (in preparation for my dissertation on the Garigliano Crossing), again a huge subject, so I am looking to tighten it up to one aspect.