+1 to the above. Another thing is to not just regurgitate what the other person has written.
Also, it's something I used to do a lot before I really got into writing and that's the whole Carrying On Two Conversations In Two Different Paragraphs problem. Which is when in the first paragraph your character responds to Hi how are you, and says well no i'm shitty today sucks, and then some thoughts about why today sucked and how they really just want a hug from the other person but won't ask for it becuase of reasons.
and the next paragraph you do some actions and then bring up another topic, as one would in a conversation, and then a few tags later you have a huge amount of conversation in the top paragraph that has nothing to do with what the pair is doing in the bottom.
When I notice that happening, I try to wrap up one or the other topics, and just have one going because if you think about a conversation you're having with someone it's about the thing you're talking about right now, x says this. y responds, back and forth, but you rarely ever have two convos going at once.
the other thing is to have some sort of movement, but don't pull the other character around or feel like you need to be doing everything in every tag. when characters speak to each other, someone should have a quirk like biting their lip or rubbing their neck or whatever it is, depending on the conversation they're having. don't make it a routine like action though. you just wrap it into all of the things you're talking about. watch your overuse though