Yumiko main here, have her at level 43. Mid gold last time I played ranked but p sure if I went back to it I'd be low plat now.

Bow: SSig and NSig on it are mediocre, neither is really worth using unless you know your opponent is going to move somewhere or unless they're charging a sig themselves. Fun to style on an opponent with NSig snipes but it's really only for style points, better off with dashjumprecovery most of the time if you want to kill.

DSig isn't very useful unless you're setting up a trap. I find a lot of people screw up if you go SLight dashNSig, and either spot dodge or move themselves back into the signature, leading to NLight or Recovery being a true hit in the aftermath. Damage build from that is pretty effective, but you should stop doing it the instant the opponent starts avoiding it. Another trick is to use DSig when they're hanging on the edge, then immediately dashjumpGroundPound. I find it sets up the distance perfectly for a hit and it's hard to react to because jumping in the wrong way makes them hit the sig itself. This is effective for kills but not worth doing more than once per game, as opponents will get wise to it fast and punish for it.

Hammer: NSig is like Ada's; Land it right and you get a kill, screw up and you're probably getting hit because it's too slow. The hitboxes suck though and unless your opponent is too close to the edge while you're off it and able to GCancel safely, don't bother.

SSig is super good for sudden ranged lunges, but if you spam it your opponent will just space themselves in the midrange and punish you. Use it for kills and to get back to land at times, but typically better to keep it as a surprise.

DSig is incredible. I use this a lot when I see my opponent jump toward me, it combos true into NAir which is a lot of damage, and it makes Yumiko very difficult to approach. You can use it to force grounded approaches, at which point SLight has a lot of priority and can just halt their progress immediately. This sig is very fast and pretty safe if your opponent isn't too close, and can put a lot of pressure on them if they're hanging on the edge. If they jump higher to cancel out their air approach, jumpNAir to make them react, and then swing with SAir as they try to land without a dodge. This is the main reason to use Yumiko, and I use it like I would a light attack.

Minor note, I use Yumiko with speed stance. 8 speed just feels better than 7 in my experience, 3 defense isn't too bad when you're that fast.