Rule 13 of 17 · Chapter IV — After the Date
If you had a good time, commit the bold act of saying so
Why this rule exists
Prepare for vulnerability of an almost reckless order: when you enjoyed someone's company, you tell them, in clear words, reasonably soon, without hedging it in irony or making them guess. The done thing is apparently to play it cool, to leave them wondering, to ration your enthusiasm as though it were a scarce resource that loses value when spent. It is rubbish. There is nothing cool about making a person who likes you feel anxious about whether you liked them back. A warm, plain 'I had a really lovely time and I'd like to see you again' is braver and more attractive than any strategic silence, because it takes the small risk that so many are too frightened to take, and courage of that gentle kind is deeply appealing.
In practice
If the date was good, send a simple message that night or the next morning saying you enjoyed it and would like to do it again. Be specific if you can, name a moment you liked, because it shows you were actually present and not just being polite. Do not bury the sentiment under so many jokes that the sincerity gets lost; a little earnestness is the whole point. Then let them respond in their own time without spiralling. You have done your part honestly, and whatever comes back, you were the person who said the true thing kindly, which is always the right side of the ledger to be on.
When it doesn't apply
Enthusiasm is not pressure. Saying you had a good time is warm; sending fifteen follow-ups when they have not replied is not. Say the kind true thing once, clearly, then give them room to answer.