Challenge to duel people with shards that are bad at fighting, I went full duelist and learned all the stances, also make a disadvantaged duel to tempt them more if you are confident.
When they are low on HP, although its against the rules if you can kill them you get the shards!
Or plot a scheme to murder them :p
I was able to rise from a low rank, and after some generations I have 3 shard blades and a shard plate in my family now!

Becoming 3d radiant also worked for me, u can create ur own shardblade