The colon is a strong punctuation mark that points readers ahead to the rest of the sentence. Colons shouldn’t be overused; perhaps one per page, if that.
I begin each day of my life with a ritual: I wake up about 5am, put on my workout clothes, pour a cup of coffee and head to the gym.
The composer Igor Stravinsky did the same thing every morning when he entered his studio to work: he sat at the piano and played a Bach fugue.
Colons have other uses – mostly formatting times, bibliograph entries and similar.