The two most common prepositions used after the verb "think" are "about" and "of." They are very similar, but there is a small difference.
Usually when you think of something, it is a brief moment - just a few seconds. It is also used for opinions. When you think about something, you are considering it for a longer time - like a few minutes or more.
Every time I hear this song, I think of my mother.
(thinking for a few seconds)
What do you think of my new haircut?
I'm thinking about moving to a different city.
I still get angry when I think about all the rude things my sister said to me. (thinking for a few minutes or more)
Common error: Don't use "think to" for "considering."
I'm thinking to do an intensive English course in Canada.
I'm thinking about doing an intensive English course in Canada.
In daylight, stand in front of a mirror and hold your favorite garments to your face. Do the colors still suit you? If hair and skin have faded a little, you might need to adapt your palette. Rich tones might suit better than washedout pastels; chocolate or charcoal can be kinder than black; green tones play down flushed cheeks; and creamy tones near the face reflect illuminating light upward.