How to end a first date, and set up the second

One straightforward way to end a first date is to say honestly how you felt, then say goodbye in whatever way you both seem comfortable with. Something like: "I had a really good time. I'd like to see you again." Then a hug, a handshake or a wave, depending on how the night went. The rest of this covers how to read the moment, when to call it, and what to do in each case.

Read the moment first

You can't read minds, and nobody can. What you can do is notice behavior. These are hints, not certainties.

Signs she's enjoying it:

She asks you questions back and follows up on your answers.
She stays past the time you'd planned, or suggests staying.
She brings up future things ("I've been wanting to try that place").
Her attention is on you, not the room or her phone.

Signs she may be winding down:

Short answers and few questions.
Glancing at the time or her phone.
"I should get going" early on.
Long silences that nobody picks up.

One caution. Some people are quiet when they're nervous and warm up late. A single sign proves little, and signs of interest explains why a pattern is more reliable than any one moment. When you're not sure, the easiest fix is to ask, which comes up below.

Choosing when it ends

A common piece of advice is to end while it's still going well, not after it fades. That's an opinion, and the research below doesn't settle it.

There's research on why timing is hard. Mastroianni and colleagues published a 2021 paper in PNAS on when conversations end. In one online study, 806 people recalled their most recent conversation, mostly with a partner, family member or friend. In a lab study, 252 strangers talked in pairs for anywhere from 1 to 45 minutes. The authors report that only about 2% of conversations ended when both people wanted them to. The study also found that people were poor at guessing when their partner wanted to stop. The work was about conversations in general, not first dates, and it was descriptive, so it doesn't show which approach works best.

One practical reading is to say the quiet part out loud. Two easy ways:

Set an end time up front. "Let's do coffee, about an hour" means nobody has to guess.
Ask near the end. "I'm having a good time. Do you want to get another drink, or should we call it here?" It gives her an easy yes or an easy exit, and both are fine.

If you've both got a plan for later, ending on time and warmly is a good outcome, not a bad one.

What to say, in three situations

Honesty works better than a script. These are examples to adapt.

You'd like to see her again:

"I had a really good time tonight. I'd like to see you again. Are you free Saturday? I'll text you tomorrow to sort out a place."

You're not sure yet:

"Thanks for tonight, I enjoyed it. I'll text you."

Only say it if you will. It leaves you room, without promising something you don't mean.

You don't want a second date:

"I enjoyed meeting you, but I don't think we're a match. I wanted to tell you in person. Take care."

Short and kind beats a promise to text that you won't keep. If saying it in person feels too hard, a brief, polite text the next day is better than silence.

If she's the one who isn't sure, her answer to "I'd like to see you again" might be "Let me think" or "I had fun, I'm just not sure." Take it at face value. Don't ask her to explain. Handling rejection covers the part where it stings.

The goodbye itself

You've got three normal options: a hug, a kiss or a wave. A common approach is to follow her lead and give her an obvious chance to respond.

Hug. Often the easiest. Stand at an easy distance, open your arms a little and let her step in if she wants to. A handshake or wave is fine too.
Kiss. Ask first: "Can I kiss you?" Go ahead only on a clear yes. Silence, a pause, a laugh, turning away or stepping back all count as no. It's quick, it removes the guessing, and a clear yes is a good moment. First kiss: how to know when has more on the build-up.
Wave or "talk soon." If it's a clear no or a maybe, a smile and a kind goodbye is a clean ending.

If she says no, turns her head, steps back or doesn't respond, that's a no for tonight. Say "No worries, I had a good time" and keep it light. A no means stop, and that goes for any invitation she declines, including a drink or coming back to your place. You don't need to persuade anyone. Consent and respect goes through it in more detail.

The practical bits

Sort the bill before the goodbye. Pay or split, then walk out with nothing left to settle.
Offer to walk her to her ride or the station, and drop it if she says no. Some people prefer to leave alone. Asking each other to text when you're home is fine if you both like the idea, and not worth pressing if either of you doesn't.
Don't linger. A long, awkward doorway moment drains a good evening. Say it, do it, go.
Text the same evening or the next day, a rule of thumb, not research. Keep it simple and specific. What to text after a first date has examples.

After you part

Your head will replay the night. Judge it by what she did, not by your memory of your own worst moment. If she said yes to another date, set it quickly and make it a plan with a day and a place. If she didn't reply or declined, you've learned something useful and you can let it go.

If you use Run Game, Stats has an outcome funnel with "date set" and "went on a date" stages, which lets you see how many conversations turn into dates over time.

What to do next

Set an end time when you make the plan. "About an hour" or "until 8."
Pick your ending line in advance, one for "I'd like another date" and one for "this was nice." Practice saying both out loud once.
Settle the bill 10 minutes before you plan to leave.
Stand at a normal distance for the goodbye and let her choose hug, wave or more. Ask before a kiss if you're unsure.
Send the follow-up text within 24 hours, short and specific, and make the next plan concrete if you want one.
Take a no without a debate. One friendly sentence, then you're done.
Write down two things she did that suggested interest or none, and judge the date on those.

Sources

Scientific American, "People literally don't know when to shut up, or keep talking, science confirms", on Mastroianni et al., PNAS, 1 March 2021.