By request here is a brief demonstration of the way I usually do it. Whether from life or photo it starts with an image that is interesting. This photo will do nicely. Study the picture and determine the outstanding features. Look for contrasts in shape, size, and proportion.
First lightly sketch the basic shapes. Keep them simple and distinct. Watch for straight lines and curves, for contrast. Big shapes next to small ones. This is a semi-realistic caricature but sometimes go for really cartoony.
Then use construction lines to describe the volumes and shapes. This step can be the first if you prefer.
This step is where I sketch in the expression and certain key features. Keep it light at this stage.
Then start darkening the key areas like facial expressions with sharp pencil or pen if preferred. Use bold lines for outlines and undersides of key parts.
I've been enjoying rap since Rapper's Delight (In Texas the accent is on first syllable in De-light). John K. seems to think it sucks which is confusing to me since he always has great taste in music. Oh well, you please some of the people all the time and jerk the rest off.
Stimpy as a whale from Untamed World. There's word going around that blogs are history. Well, I like my little blogohood and the word is fun, as is google, etc. I hope to keep it but just in case, I have started to develop my own system for web chatting - Digital Uplink Macro- Phase, or D.U.M.P. for short. Soon every one will be taking a D.U.M.P. on the web.