Searchers in niche industries/areas - how did you choose or target these areas?

Hi everyone, coming back into search after stepping away for a few months. I was taking a more generalized approach (targeting any businesses within a particular size, EV and multiple) but have decided to narrow down focus on particular industries. For those of you who have taken this approach, how did you find and select markets/industries/areas of focus? What kinds of tools did you use for research and market analysis/data? What was your sourcing strategy? Would appreciate any input or guidance here. Thanks!