One thing I would do (having learned from experience) is to catalogue and photograph existing damage to the windows etc (that you could potentially be blamed for).
Send the list, along with the photographs in an email. That way they will be less likely to blame you for any existing damage.
Other than that, letting agents are usually very good to work for. We do work for 4 different agents, and they are all professional and pay within a few days of sending the invoice.
They are also chill about windows that can’t be done for whatever reason, such as power lines too close or that it would require standing in the road (which we will not do). The response has always been “sure, fine, we understand”. That’s a contrast to owners who will often greet that sort of thing with a sour look.
