Sliding into DMs is like the new going up to someone randomly at a bar to try and talk with them.....knowing what to say is half the battle and pickup lines are corny....According to Elite Daily here are some messages that can help you....
Respond to one of their stories.
Ask them about something they recently did.
Send a post you found that reminded you of them.
Bring up a mutual friend.
Invite them out with friends.
Ask for tips if you’re new to city.
Call out their previous interactions with you.
Be forward with your feelings.
Be bold and ask them out.
And if those don’t work.....Remember, you want someone who is excited to talk to you. If that’s not them....THANK YOU, NEXT!
Source Elite Daily