Silver tounge

I’m looking for idea’s and suggestions for those people who would like to persuade neutrals to there side of the game. Is there a formula people use some kind of software? :smiley: I realize that once game starts some nation have requests like staying out there map region, not landing on there pop centers stuff like that i know. But if you joined a new game that is beyond turn 10 and there are 2-3 nations still undecided that have chosen a side, what then.