alveolar: tip of tongue touches the gum line behind the teeth (the alveolar ridge)
bilabial: upper and lower lips come together
labiodental: lip touches the teeth (Usually it is the lower lip touching the top teeth; however, an equivalent sound can technically be achieved from the reverse.)
dental: tongue interacts with teeth either by being placed between upper and lower teeth or against back of upper teeth
post-alveolar: tongue is placed right behind the gum line behind teeth
palatal: tongue is raised against the center of mouth roof
velar: back of tongue touches or is held close to the velum (soft palate)
glottal: air sound is produced by stopping flow to glottis
labiovelar approximant: lips and velum both constrict – but not completely (Read more about approximants here.)