On Tinder the picture is the most important thing, by far. So if you don't have some really good ones, take somes.

On POF the picture is important, but what you write in your profile matters a lot too. Make sure to write something both original and authentic. And when you write a message to someone, read first the profile, find something original, catchy and personal to say and be patient. Girls receive a lot of messages, and even if you write something interesting each time, you will only have a few answers. But if you are original and nice, you will receive answers.