As we have known its meaning, it can help to appreciate the evolution history of "意". ( image get from http://www.vividict.com )
|Learn one Chinese Character a day - 意|
Seal Script is then evolved to plus , by replace "口" with "心" to make it clear that "意" means "Sounds or Tones of your heart".
Clerical Script, Regular Script and till current way of writing - "意", they are just continuation of Seal Script with simplifications along the way.
Now let us enjoy a Chinese Calligraphy with "意" inside: