Scenes and dates are both better when there's chemistry between the people involved.
Chemistry is a thing that can be developed over time and it starts with effort. If you make an earnest effort to find something you like in your scene partner, chances are that you'll find it. Be patient and don't expect magic to always happen immediately, the relationship will develop if you keep at it. Eventually you'll find where you and your partner line up (easier in scenes than in life!).
Don't just talk, do something!
Talking heads scenes and dates where you just sit and chat can work out all right sometimes, but a lot of the time they are boring and fairly unrewarding. Instead of just sitting and talking, maybe try an activity. Hike, paint, cook, anything to keep you from just blathering on from one unimportant thing to the other. In a scene, it's more interesting to watch people do something physically than talk. On a date, it's more interesting to do something and it also takes the pressure off of everyone to be super clever at all times. Lord knows I'm guilty of talking head scenes and chatty dates, but the activity-based ones are always better.
Forget stuff, talk about how the other person makes you feel.
Now, I'm not telling you to just recite poetry and make googoo eyes at someone instead of sharing information about your life. I am, however, saying that you shouldn't get so carried away with your own cleverness that you forget to be a human with emotions. Most experienced improvisers can weave a joke or story out of any subject, but instead of doing that we should practice just letting some stuff land on us and having a real reaction to it. Tell your date that they look nice. Tell them if you like them. Tell your scene partner if you think they're a crazy person (tell this to your date too, I'm sure it'll work great).
Maybe just listen for a little while.
Talking is overrated, find something your date likes a bunch and just engage with that as much as you can. Hopefully they'll at least be interested enough in you that they'll ask you questions about yourself and sit back and listen too. Either way, go into both a scene and a date with the idea of hearing and caring about everything the other person has to say and it will almost certainly turn out for the better.
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There you have it, I've solved both improv and dating. Now if only I could put my theory to use in either context!