The best way to avoid the many trolls, Russian agents, and nazis that Twitter is eager to host is to stop using Twitter. The next best thing might be to use "soft blocks," as described by Barry Ritholtz on his The Big Picture site.
Enlist mutes, blocks (soft blocks, too) and reports: Use these tools to manage your flow and keep out the unruly elements. My rule is that I mute the annoying and block the intellectually dishonest. The truly dangerous and offensive jerks get reported (doing this helps the community police its worst elements). And you can import other people's block lists via a free service called Block Together (but it can result in some false positives, meaning some blocks you may have wanted to keep).
I also have been known to "soft block" people, a quick block/unblock and mute so that a) they no longer follow me and b) I no longer see them. It reduces the jerk factor dramatically.
Avoid forecasters, too: When they are correct, it's mostly random, and when they are wrong, the advice is hilariously expensive. Steer clear of the relentless self-promoters. When PR people tweet at me, I not only block them on Twitter, but I also blacklist them everywhere else I can.
Be wary of blocking people whose views are diametrically opposed to yours. Try to find people with whom you can respectfully disagree. This will encourage you to be civil and help you avoid creating your own biased ideological bubble.
Finally, keep clear of the jerks. The world has 8 billion people in it, and if only one-tenth of 1 percent are jerks, that is still 8 million people you don't need in your life. Focus on the positive contributions made by the other 99.9 percent.