The rules about texting after a date are mostly invented. The three-day rule, waiting for them to text first, sending something very casual versus something direct: none of it matters as much as people think.
Forget the old rules
What actually matters is: do you want to see them again? If yes, say so. The sooner the better.
What to send if it went well
Something like “Had a really good time tonight, want to do it again?” is direct, clear, and gives the other person something easy to respond to. It doesn't require them to decode what you meant or wonder if you had a good time.
If the date went well but you're not sure how they felt, a light message the next day works perfectly fine. A reference to something you talked about, something that shows you were actually paying attention, lands way better than anything generic.
When you're overthinking
If you're staring at your phone without knowing what to say, Charmlet can help you draft something that matches the vibe of how things went. Paste in a little context and it'll give you a few options to work with.
Related reading
How to ask someone out on a dating app · How long to talk before meeting in person · How to revive a stalled conversation