-- Below is how I mitigate that in my world, but if anyone has good strategies/tactics to handle such scenarios, please share!

Being well-informed means going in with the best possible knowledge. Of course, there's always the chance to step on a land-mine, but more often than not if you put in the work you can learn everything you need to know to frame the negotiation in a constructive manner.

Some really important points that are relevant for what I do (and may help others!)

1. Who are the stakeholders in the negotiation? Is it the person I'm speaking with, their superior, or a party much farther removed (shareholder/board member/internal influencer) that must be identified.

2. Who in their company is responsible for the information I need, if such a person even exists? Can I address the relevant questions directly to this person? (Sometimes this is as easy as sending an email and literally just asking. Sometimes not)

3. What are their high-level goals? If they are a public company you can glean a lot from their public reports and financials. Sometimes you can find out that you're basically swimming upstream, and sometimes you find out that your counterpart is basically mandated to make certain decisions.

4. Is there any visible progress towards their goals? If they're struggling to make headway, and you can identify this, you can re-focus the discussion on making their pain point go away. (This depends heavily on what you do, but for my field, I can almost always find accurate information)

Ultimately, the prep work for a serious negotiation is what we internally call CIA work. It's a lot of intelligence gathering, asking (sometimes indirect) questions to get some insights, and doing the due diligence to ensure that we're as informed as we can be. Even with all that effort negotiations still fail sometimes. But if they fail, it's usually because the type of deal that would be struck wouldn't make sense in the first place.

Of course, this doesn't apply to hostage negotiations or to what I could only describe as 'toxic' scenarios.

The assumption here is that you have access to that knowledge. In many cases, you just don't. You can't address it by emails or talking to anyone. All these scenarios aren't necessarily 'toxic' but common in daily life.