The best thing about texting is that you can check what you're saying before you send it. No matter whether your chatting via text or video, the goal here is to make your girl feel like she's the only girl in your life. Tell her things that make her feel unique and special. That she's the only girl for you or that you can't live without her. Most girls love cheesy cliché lines.
Dont do that then shell think that your lying to her and you dont actually feel that way. Tell her she is the most beautiful and smart or whatever and compare her to other people and say she is better than them but make sure to not compare her and her friends. Compare her to the girls that she thinks are better looking or more popular than her.
compliment her on the little things about her , maybe her laugh or something cute and silly like her dimples . haha, or send her a poem that you made by yourself and read it to her over a video chat ! and make little signs that say "i love you" and show them in the camera.
Send her random texts throughout the day to let her know you're thinking about her. Tell her she is beautiful or gorgeous. Don't use the word "Hott"! Make them short and sweet for example " hey beautiful, just wanted you to know I was thinking about you"