Amazin as ur art always is :)*

Hi Palanqueta... you just have to pick your subject matter wisely.. and if they catch u looking at them, just give them a nice warm smile back :) They'll think you're just playing videogames on your Nintendo :)

Palanqueta.. i can also give you this advice.. when drawing someone, look at the 'negative space' of the person. i will explain: imagine the line drawing of the person to be the 'positive' space. the outline, shape, postition of certain features etc... So when observing someone as you do, put those marks down on the sketch as well.
It's hard to try and memorize what someone looks like. So then check your drawing in progress, to the model you are drawing. Now this is where the 'negative space' comes into play. How far away is the tip of the nose to their eye, how far apart is it from the ear, to the cheekbone? how far apart is it form the cheekbone to the nose? These observations are like 'fact checking' constantly going back and forth from your drawing and then comparing it the the subject matter. another example of this is: if someone is standing with their hands on their hips, what does the space between their arm and their body look like. That is the 'negative space' i am referring to. Constantly compare from your drawing to the subject matter.
So - do this constant comparison with the features of someones face. and draw it. and then compare, back and forth. I hope this makes sense, Cheers!