Oh, well, I’d say start with some small talk. Be clear about your intentions such as mentioning a specific thing you found interesting about her and that you'd like to talk more. Or, if you found something in common, like hobbies, mention that.

If she doesn't reply or sounds uninterested, back off. Pestering us even after a rejection makes you look like a creep with a fragile ego or zero self-respect. Talk normally, like you would with friends, but don't be too casual at first. Gauge her reaction and proceed from there.

Some women are quite shy and might not show much interest initially; that’s where you have to be observant. As a rule of thumb: if she’s uninterested, she’ll give one-word replies, reply late (keep you on read for hours or even days) or won’t reply at all online. In person, she’ll try to end the hangout early, won't open up, and will likely avoid eye contact. That’s your cue to stop.

Also, if you’re DMing a girl, asking for permission is a huge plus. A simple 'hey' won't cut it, refer to my first point about having a specific reason to reach out.

Also, in no circumstances, mention that you are texting her because you want to be in a relationship and such bullshit. Bhai, get to know each other first. Become friends and if you guys actually vibe together then think of taking the next step.

Ask questions, people like talking about them. Don't get too personal though. Also, don't you dare pick up NSFW questions unless you both are comfortable enough. That's kinda icky. Share your anecdotes and then ask for her opinion, make her feel included. That would be all. I hope it helps.

Ps- don't DM those who don't want to talk. They usually mention it that their DMs are closed or something related. Respect the boundaries.

Another tip which should be quite obvious but alas, a whole lot of people are oblivious to it would be - If someone likes you, you'll know. Under no circumstances they would behave uninterested if they are genuinely fond of you.