There are a few techniques by which some designs may be readily perceived by our eyes like 3-D designs. An example of this type is to be found in this video: just by tracing the lines of our hand and using several colors, the result is quite amazing – a hand in three dimensions.
To create a three-dimensional drawing, straight lines need to be alternated with curved lines. Try this technique: place your hand on a sheet of paper and draw the outline of it. Next draw the horizontal lines; curve the area with the contour of the hand and then continue with straight lines beyond the curve. Repeat drawing lines to cover the contours of the hand with curved lines, and the rest of the space with straight lines.
For the drawing to have the desired result, you can use colored markers to trace the outline. It is true that you need a lot of patience to be accurate, but the result will be impressive, as this technique will make the outline turn 3-dimensional.
“Patience is bitter, but its fruit is sweet.” (Jean-Jacques Rousseau)