I dont do SOR, but I thought that I could share some input.
How I memorise information for modern history:
Conceptually: Know one event. Know why it happened, and what happened from it. This cause and effect really helps because its such a logical process
Personally: The Night of Broken glass (uprisings against the jews) happened in 1938. (nineteen-dirty hate). The Night of Long Knives (Hitler turns against his friends) happened in 1934 (nineteen-dirty whore)
Word Game: The annexation of South East Asian territory by Japan in their 6 months of rise? Philippines, Hong Kong, Thailand, Malaya/Singapore, Burma, Dutch East Indies, New Guinea, Australia (People Hate To Make Sandwiches Because Danger Never Alleviates)
Stats: Things like death counts and shit. I find that as long as I'm in the ballpark, and write confidently, no one ever calls me out for making shit up.
Fyi: Australia was bombed by Japan 72 times (probably) but never occupied.