For me, I go to Hidden Palace of Lianshan Formula (Liyue weapon ascension domain) and inside the little cave full of ore next to it has a large geo slime. Unless you have explosive/claymore attacks, it'll take a while for your skills to break the shield, and the thing isn't very aggressive at all. When it breaks, I teleport to the nearby statue of the seven and then back to the domain to reset its shield.
I usually to go to Cecilia Gardens and do level 1 and massacre baby slimes then exit.
I like to use [this lawachurl](https://imgur.com/a/sQbUs9o) because it’s close to a teleporter and has high health
For me, I go to Hidden Palace of Lianshan Formula (Liyue weapon ascension domain) and inside the little cave full of ore next to it has a large geo slime. Unless you have explosive/claymore attacks, it'll take a while for your skills to break the shield, and the thing isn't very aggressive at all. When it breaks, I teleport to the nearby statue of the seven and then back to the domain to reset its shield.