So when i used it i only messaged people if they seemed to have similar interests to me. do they have a picture from somewhere they traveled? bring that up if you like travel, if you've been there or want to go there.

Do they go hiking in their pictures? ask them where it is or ask them more about what they're clearly interested in. I found it the easiest way to break the ice because people love talking about what they're interested in, especially if the other person likes it too. Makes it easy to move to other basic conversation, and if it goes well, ask for their number/super casual date early that's based off the mutual interest.

Even if it's something not easily done together (such as travel), ask to discuss more over coffee or drinks "because i'd love to hear your stories about [said interest.]" Just be genuine.

When i started doing that i began having way more success conversing and meeting people. Even when it didn't work out, i made several friends who i'm still in touch with years later.