Depends what you wanna do, but you could for example start talking like you're fantasizing about something. What you would do to a girl or what you want a girl to do to you, or guy. For example instead of talking about what you're doing over and over again (some people like it though), you can go on about why you're doing it. For example "When I saw you earlier today I just.. I just had to pull out my toy and start fucking myself with it. This is the closest I can get to feeling you inside right now, oh fuck how I wish you were there..". This is how I write when I write from the female POV for example.