Do not apply heat to the face unless your dentist instructs you to do so, since this can increase swellin.
Avoid forceful spitting, use of straws, sucking. These things may interrupt the formation of a blood clot & the wound may start bleeding again.
Smoking, especially, after a lower molar extraction can prevent the blood clot from forming, causing discomfort and increasing healing time.
Hot liquids will tend to dissolve the blood clot that has formed in the extraction socket, so avoid them for the initial 24 hour period. Also, you should avoid alcoholic beverages for at least 24 hours.
Avoid strenuous exercise or other such activities for 24 hours after your tooth has been extracted. If you lie down, use an extra pillow so to elevate your head.
While your mouth is numb, be careful not to bite your cheek, lip or tongue.
Do not use commercial mouth rinses. They may irritate the extraction site