So this is just some ramblings on how I view Gambits.

In my opinion the value of a gambit is always established in its prep work. Simple questions to ask yourself may include:

What information will this gain my team?
How should I interact to draw this information out?
What risk does it bring to my team?
How can I limit that risk?
What is my 'escape plan' to reveal it was just a gambit and avoid a lynch?
What can I do prior to executing the gambit to increase its value?

One thing that can make a large difference is seeding. I have seen this done very effectively to both increase its chances of drawing out information as well as to 'escape' pressure and reveal it was a gambit. For an example:

I'm having trouble shaking the feeling that Jake is scum.
Not that he couldn't be town. But his interactions with Tom look really bad.
Sheriff may be required to sort that players alignment.

That post looks innocent enough but it sets up a play for me to fake claim as Sheriff with a peek on someone. I could reference it to show 'See, I seeded here softing I was sheriff and would check Jake. I checked him last night and he came back Mafia.'

Then after the gambit has run its course I could point to it again and say "Read the first word of each line, I'm Not Sheriff. it was a gambit."

Using seeding effectively can both prevent a misslynch as well as increase the faith others will place in your fake claim.

I would also recommend thinking through what specific behaviors would indicate which alignment if you are counter claiming or voicing a fake night action prior to executing.

Imo the best gambits are those that do not focus the entire day chat on you or put you in a 1v1. The more subtle the better and in general I avoid them. In my experience the majority of the time someone pulls them it just outs a TPR or causes a misslynch. I doubt there is a single player on this site that can name a time they have seen me shut down chat and place myself in a 1v1 with a fake claim.