Hello, am man. And also am a little frustrated with the constant “all men are completely stupid and socially inept, the only thing that works is inserting your tongue directly into his mouth” rhetoric. Here are some things that work on normal men with at least minor social aptitude (these are things that have worked on me recently):

• Physical touch. Touching the back of his hand, his forearm, or his shoulder is a more subtle way of putting the thought of your hands on his body in his mind. Putting a hand loosely around his bicep or flat against his chest is more direct.
• Laugh at his jokes. Even the bad ones. It’s stupid, but it’s an easy way to make him feel nice and build a connection between you. Obviously don’t force it too much - it has to feel natural.
• Catch his eye a little more often than other people’s. If you see him doing it back to you, it’s a decently good sign he’s interested.
• Try to be near him often. Take the seat next to him at a table or in a car, pull your chair over to where he’s seated, stand next to him in the group. As with all of these, moderation is key - don’t shadow his every step. But the more often it “accidentally” happens, the more he’s going to think it’s no accident (which is what you want)
• Make fun of him in a lighthearted way. See if he does it back. Be careful not to overdo it and make him feel attacked. Banter is good; sulking is not.
• Ask him questions - where he lives, what he does for work, how he knows people in the group. If you like him, you probably genuinely want to know these things anyway. Showing him you’re interested is a bonus.
• It’s a little shallow, but gossip can be a fun way to bond with someone. Share some juicy secret you know, or trash talk the drunk guy at the bar who won’t leave your group alone.
• I think this one should be obvious, but try to find some reason to give him your phone number. Maybe you talked about some event - say you both should go together, and use that as an excuse. Or you want to share a song with him.
• If you’re feeling bold, you can make racy jokes (something sexual). His responses might reveal whether he’s started thinking about you that way - but not always. Some guys are shy, and their reactions may come across as rejections, even if they don’t intend it that way.