If they have a search warrant, let them search.
If they have an arrest warrant, peacefully surrender. And repeat the phrase “I would like to speak to my lawyer” until you speak to a lawyer.
If they say they would like to “talk” to you about something; You say “Fine, you can talk all you want, I have nothing to say.”
Then pull out your phone, hit record, and watch them scurry away.
As a matter of policy, they will not under any circumstances record themselves, or allow themselves to be recorded.
TLDR; there are only two appropriate phrases you should ever say to the FBI: “I want a lawyer” (if you’re under arrest) and “I have nothing to say” (if you’re not)
**EDIT- according to the comments using the phrases “I would like to speak to MY lawyer [insert name of lawyer] and “I am invoking my 5th amendment right to remain silent” are superior. They are probably right, IANAL. And even if I was ANAL, I’m not your ANAL.
PS- if you work for the FBI and you’re reading this now, eat a bag of dicks.
You might also want to specifically state, "I'm invoking my right to remain silent and would like to speak to a lawyer," since it was recently ruled that silence can be a factor for incrimination. It was a bullshit ruling, but one everyone should know about.
Also, if you're broke, an attorney (public defender) must be appointed to represent you free.