I heard the first story from an old yid about a maggid in Lita who only had one drasha. It was apparently a very old trick.
1-Call ahead to ask what you can bring and what time to come.
2-Come on time, with what you said you’d bring. Even if they said “nothing” some flowers or a bottle of wine is a good idea.
3-Offer to help (yes, even men.)
4-Compliment them on their kids.
5-Talk to everyone including the children.