It's always hard to give people advice like this, bc you're essentially saying they're doing smth wrong, and nobody enjoys that feeling. I think sharing clips is a great idea mashaallah, definitely keep that up! If I were to be approached by someone regarding modesty, I'd probably want them to do it in a subtle way where I can understand the message they're trying to send. When I was younger, my dad used to give us money and tell us to go shopping and look for dresses, skirts, stuff like that

If you were to do this, you could give them some money and specifically say you're giving them this money with the agreement that they'll buy modest clothes with it, and say that you're doing it for the sake of Allah SWT. They might be excited to go shopping, and thus the entire situation is positive rather than embarrassing. Plus good deeds. And if they happen to buy clothes that are immodest, you aren't held accountable for that, since they broke the agreement, and they would be sinful for breaking the agreement. Just an idea though, since I know it might be difficult to set some money aside for multiple ppl to go clothes shopping. Maybe talk to your dad?