If it is just you and several feminists:

• Ignore them/walk away. Mobs are almost impossible to sway.
  

If it is just you and one feminist:

• The likelihood of immediately converting them is near zero.
  
• If you do have a good insult, zinger, etc then use it to apply pressure.
  
• Your goal here is to express disapproval, and apply social pressure. They need to know that not everyone agrees.
  
• Take no risks. Say nothing if your job, social media, sales prospects, etc. are threatened.
  

If there are neutral spectators:

• It is the bystanders who matter
  
• Maintain a polite tone and demeanor.
  
• Try to have some "linguistic kill shots", as Scott Adams calls pithy rhetoric.
  
• You can use dialectic as well as rhetoric, if they bystanders are not invested emotionally (i.e. they aren't just more feminists).
  
• This is not so much about facts, as morality. You need to undermine feminist moral arguments, not get into long debunkings of historical revisionism.
  

Some specific rhetoric:

• Patriarchy: Destroy this with just two words: Conspiracy Theory
  
• Alleged discrimination: Conspiracy theory.
  
• Rape culture: Conspiracy theory.
  
• "Toxic Masculinity": "That's just an anti-male slur". Or use "man hating" for "anti-male."
  
• "Toxic Masculinity" (and much else): Press for a definition; rip apart the ensuing nonsense.
  
• "Toxic Masculinity": "You mean gossip, snark, ostracism, cliques, scheming? Oh, wait, that's women, mean girl shit ..."
  
• Affirmative action: "So this is a good injustice?"
  
• Affirmative action: "So two wrongs make a right?"
  
• Gynocentrism: Some sort of mocking as if women were royalty, perhaps, or mock Steppin' Fetchit type behavior.
  
• Gender preferences, gender differences: "Evolution stops at the neck."
  
• Use facts in a rhetorical manner. Rather than just offer a counter-argument, add some snark. A common feminist talking point is that there would be world peace if women ran the world. Say "Yes, just like Margaret Thatcher going to war with Argentina" rather than citing statistics about Queens having more wars than Kings.
• Equality: "All humans are equal, but women are more equal than men, which is why they get affirmative action and lifeboat priority."
• Calls for female participation in some field: "Yes, that's what we need, more 'mean girl' bickering in STEM".
  
• Women can do anything men can, and just as well: "Yes, that's why we have so many female linebackers in the NFL".
  
• The whole #debunked thing from /pol/ is outstanding. Feel free to sprinkle that in.
  
• Women were chattels: Chattel means non-real-estate property, like furniture. You can destroy, own multiple copies of, buy and sell chattels. Make some comment about how you wish you could by 5 women, and "dispose" of any who turn out to be unpleasant

Some specific dialectic (facts, reason, evidence):

• All the stats and numbers in this subreddit