We always insist on a voice call or video-chat early on in talking to guy. That scares off a lot of catfish and pic-collectors right away.
Then we also insist on a social meeting for drinks or coffee with sex OFF the table. That also scares off some guys who are likely to flake.
Keep in mind some people are just chatting with you with their phone in one hand and their dick in the other. They are using us for hot sexy chat with no intentions of meeting. The first clue is guys who roll out a laundry-list of sex acts they want to do. Also guys in a huge rush to get to photos or sex talk is a red flag.
The guys who work out best for us can get laid any time they want. They are willing to take the time to get to know us and have a good experience too. They have no problem chatting a week or two to set up something that works great for everyone.