Generally useful items to farm / buy for Standard?

Hi folks,

Unless the next league is something super interesting, I would likely skip it. In Settlers I managed to get my hands on about 5-6 divs (the most I've ever had in а league so far) and I want to buy a few things that I could use for builds in Standard.

I played with RF in both this and last league. Both characters roughly on the same level. Got to red maps but not quite as good for bosses (I assume, cuz I play quite casually). Should I invest into the RF build? And what would be the most efficient way? But also, I want to build around something different as well, like Cyclone or EA (or something else bow related).

So is there something specific I could get to push any of my characters further or maybe something generally good that would be useful in various different builds?

Thanks!