This isn't exactly an answer to your question, but I think a helpful habit is to not immediately dismiss alternative ideas. Try them out a bit and see if they fit with things you already "know to be true" and if they help explain anything else. If they survive that, reflect on why you wanted to dismiss the idea in the first place.

Ultimately, I think of "finding truth" as being a process of ironing out our own misconceptions. Everything should fit together and withstand scrutiny.