Techniques
Aside from drawing in your own style at your own ability, these techniques are general building blocks or techniques that some artists use while sketching. Feel free to try them out for some great practice!
Gesture
A quick, spontaneous sketch that captures the form, movement, pose, feeling, etc. of a subject or scene
Contour
A sketch that captures only the outline and dimension of a subject
Perspective
One-point: A type of linear perspective where only one vanishing point exists on a horizon line
Two-point: A type of linear perspective where two vanishing points exist on a horizon line
Hatching and Crosshatching
Hatching: Using closely-drawn parallel lines to create the illusion of shade or texture in a sketch
Cross-hatching: An extension of hatching that creates a mesh-like texture to create different tones
Lighting
Something to be aware of while trying to capture the shadows and highlights of a subject (Rule of thumb: strong lighting = stronger highlights and shadows