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.
Try floating on your back or your stomach as you re ready
Stay in a shallow depth so that you can simply stand up if it's not working out. It might feel weird to have water around your ears while your nose and mouth are in the air, but you'll get used to it. For extra stability, put out your arms at a right angle so that your body is in a "T" shape.