I’ve covered a fair few systems with one-shot advice so far, so here is a list with all of the posts in it:
Glorantha (not a system, a setting, but touches on Runequest/13th Age/Heroquest)
Powered By The Apocalypse (PBTA) games (specifically references The ‘Hood)
Tenra Bansho Zero
I’ve got another 2-3 in draft form that’ll appear over the next month or so – if you have any requests, let me know!