How to sketch for user experience

Everything can be broken up in basic shapes: lines, circles, triangular, rectangular.

Devices. Draw devices ... They are only a bunch of lines :)

People. Assemble basic shapes and tweak them to draw people.

Hands on devices. Start drawing simple, there is a lot you can do using only basic shapes.

To draw text start with basic lines and get the line as thick as you need!

One last thing: start simple... Most of the time you don't need more than a few lines :)

Once you have created the outline you can get fancy with the clothes.