The time immediately after you have completed your scene is very important.  It is these few minutes that can affirm that the scene was a wonderful experience or can sour what had otherwise been great.  It is in these moments that you reaffirm each participant.  Confirming that the bottom did well, reassuring the Top that the bottom enjoyed themselves and wanted what they experienced.

These moments recognize the humanity in all of us and help bring us back to ourselves.

Everyone will have different needs for aftercare.  You need to make sure you cover this during negotiation so that you know and can meet those needs.