1) Don't have your phone out or the ringer on or answer it. Phone stays away and stays on silent mode. If you have it on the table and it keeps ringing from messages and calls, it's a huge turn off and makes your date think you're probably a player. If you answer it, it will make them think you're not taking this seriously enough or even worse, that your phone is more important than the date.
2) Don't look away, especially not when your date is talking. If you're constantly looking at other people, your date will notice and it will make them think you're clearly not interested. You should be having as much direct eye-contact as possible.
3) Don't give short answers. This also shows that you're not interested. Engage in conversation, talk about yourself, but also don't forget to ask about your date just as much.
4) Don't be cold with your body language. Obviously don't touch them constantly, but a hand on the arm or around the waist here in there goes a long way in building your connection.
5) Don't flaunt your money. I don't care how rich you are and your date shouldn't either. It makes you seem like a show off and it's a huge turn off. Also, you should focus on flaunting your personality traits and your sense of humour rather than your cash.
6) Don't be too cheap. I'm definitely not saying to spend a fortune on your date, but do make an effort to at least be original if you can't afford a really nice restaurant.
7) Don't exceed 2-3 drinks. If you're getting drunk on your date, it will definitely make them question your intentions, and it's also not really a turn on..
8) Don't leave without planning another date. If the date goes well, make it even better by planning another date right away. This will also avoid your date going home and overthinking everything since they will already know that you're definitely interested for more.
9) Don't insist on inviting your date over. Sex on the first date can happen, and I do talk about why it's ok in this post. However, if you've dropped the hint and your date didn't jump on the occasion, DO NOT INSIST. Trust me when I say you will never hear from them again if you do.
10) Don't be impolite. Displaying good manners is a lot more important than people may think. Research has shown that most adults get turned off when their date is impolite or doesn't have good manners.
11) Last but definitely not least, DO NOT AVOID SPEAKING the days after your date. The rule of "wait a day or 2 until you talk to them again" is definitely one of the most stupid rules I've ever heard. In the contrary, you SHOULD talk to your date even more following your date (considering it went well of course). If you go a few days without speaking to them, chances are they will take that as you not being interested, or not being serious, and they will simply walk away, as they SHOULD.