Pretty much like Tenhou, I think the only map i actually tried to clear was Golden armor G, and it relies on luck, due to berna assassinating black armor in 5-6 hits, any more will result in 2*. But since the rate is pretty good, i do like few 3* in row.
Other than a bit of luck, brute force it with pure power.

I can post a video on youtube in day or few, or write how i do it in 1h, if anyone is interested.
Keep in mind i use Berna and Mikoto as "cheating" my way through :P (Mikoto might not be necessary though)