Smirking without your lips closed can come across as bizarre or even creepy - some people find that doing this makes them look like old-fashioned gangsters.
Many people’s smiles aren’t perfectly symmetrical, so one side of your smile may work better for smirking than the other. Practice in a mirror to determine which side of your smirk is best.
Use common sense here. Don’t leer at the recipient of your smirk for any longer than you normally would look at someone in the situation you’re in - smirks can really creepy, really fast if accompanied with a stare.
Remember - stay relaxed. Smirks are cool and confident, not attention-seeking. Don’t smirk so that you can be seen smirking, but rather, smirk as a natural response to something happening around you.
Of course, in both of these situations, sarcasm also is a possible response, so it’s crucial to have a keen eye for the context of the situation.
