Summarize:

If you started out strong, don't forget to end your conversations strong. Know when to stop texting. You can't keep conversations forever. There always comes a time when there is nothing left to say. When you feel like both of you are struggling for something to say, end your conversations immediately. Measure the response. Try to sense if the person likes you or not. If the person doesn't respond much, the person is probably not interested in flirting with you, and you should just end the conversation for good. You should set up your next interaction before you go. Say something like "Message me again sometime", or "Let's talk again tomorrow?" Don't just say "Bye!" Tell the other person why you are leaving and what will you be doing. If you are going to meet up with the person, don't be afraid to say that you can't wait to see him/her. Avoid an awkward good-bye. Say that you had fun and it was great talking with him/her. Just keep it simple and casual. Many Tinder users don't want to keep chatting through the app, as it's fairly impersonal. If you're enjoying the flirt, get their number so your chats can become more relatable. Hearing the other person's voice can do a lot for your connection. Instead of asking for a phone number, you might find more success in offering yours first, and letting the other person know that there's no pressure if they don't want to use it. Tinder is a dating service, and many people expect to be able to meet the user at the other end of the message. If you two are making a connection, you owe it to the other person to meet up at least once to see where it goes. Pick a safe location where you and the other person will both feel comfortable. Avoid the cliched "dinner and a movie" first meeting. Instead, meet for lunch or for drinks and see where the conversation goes. See this guide for more first date tips.
Leave them wanting more. Get a phone number. Schedule a meet up.