Finding Leads - Any Advice?

A big part of reaching out to leads and finding new people is cold emails and lead generation. I’ve been using tools such as apollo.io, crunchbase, we-connect, G2 and more to scout leads that fit our ICP. To be honest, the results haven’t been as great as I would have imagined. Will have to go back to the drawing board to find a better and more efficient way to find these leads. Specifically for start-ups in the tech and software industry who receive lots of customer feedback.