Comment on something interesting you find in their bio or photos
Ask relevant questions about stuff you see on their profile to show your depth and that you would be able to carry on a real conversation and are interested in them as people.
Don’t be cheesy
Pick up lines and swagger appeal to some women if that’s their sense of humor, but it’s a turn off for MOST.
Don’t ask about your personal “deal breakers” online
Save questions about height, kids, and sexual preferences for a real conversation in person. Asking about these via online chats is immature (that’s being kind).
If your online chat is going well, ask to get a drink or coffee together quickly
Don’t do it immediately, but you’ve got to express interest in meeting up quickly or you’ll lose their attention. They didn’t join an online dating service for the conversation.
Show your diversity in the pics you post
Don’t try to look “hot” in your profile pics, it will attract the wrong kind of attention. Instead, post an “attractive” photo as your featured image, then also add a classy photo (dressed up for a wedding or an awards ceremony), and a goofy or fun photo, and a photo of you doing your hobby.
Put a lot of thought into your profile
If you’re OK looking and have a decent job, it doesn’t really matter what your profile says, but a lot of women decide if you’re worth a date by that profile. Make it funny. Have someone else write it if you’re not funny.