This line would rule on me

To be honest I feel like just being simply honest should work. "Hello, I think I like you. Would you like to get tea together or go for a walk in the park and get to know each other?" But then again I'm a shut in with anxiety and little to no understanding of humans so I don't know.

This is the best way. A lot of guys are as dense as bricks and dont want to creep somebody out. Its common for most just to accept flirts as compliments, so be direct with your approach.

If you think you have bad anxiety, realize most also don't know what they're doing.
I've done this for making friends before. Just awkwardly "hey I like you, how do I stay in contact so we can be friends" basically a couple steps removed from how 5 year olds do it "hey wanna be my friend?"
Hello! I think I like you, would you like to go for a walk at the park and get to know each other?
- Hello, of course we can. Sadly we might live far apart from each other. We could chat tho.
Agreed!! Tho it’s not quite my speed. I once slipped someone a note with my number on the train because saying that out loud in a crowded public space makes me want to turn inside out. It was cute, they reached out and we went on a sort of date, and settled at friends. I’ve done similar a couple times since and it’s always been positive.

I feel like getting handed a ripped off piece of someone’s bookmark or something with their name and number is very disarming. It gives agency to the person being approached, which I think makes the whole interaction much less weird than you’d think. For a hot sec I thought about making a business card style thing, but I think that makes it weird again. Takes the “meet cute” vibe out of it when you seem over prepared for the occasion.

Worth noting I like to include my age if I do this, as I look quite young for almost 30 (I blame the HRT lol) and I just want people to have that detail before they choose to reach out or not.

Oh also the original post would 1000% work on me.
- I feel like this might the best option for shy or anxious people, you can't mess up talking cuz you don't talk and also puts no pressure on the other person to respond right away. Might try this actually but I feel like I would mess up even just handing over piece of paper to someone or look weird.
- May not be your speed, but something I've thought about re: the business card thing: Keep an eye out for interesting or odd business cards, and keep a couple with you to write your info on the back for this kind of situation. Depending on what they're for, it's a conversation starter when you meet again, and it doesn't feel as contrived as making your own cards.
  
  Small independent businesses are a good source for these, particularly if it's a decent place for a date/friend outing. Or just something odd you like or find funny.

That would convince me to go on a date

Why won't hot aliens crash land in my backyard to take me on sexy space adventures? 😩

Would work on me.

Yes. Yes i sure do

In that exact order!

If someone asks if I wanna overthrow the government with them when trying to flirt with me I wouldn’t be able to say no. Unless they were a fed that is.