Which proverb means "you can't have everything at once"?

Which proverb means "to be very careful about what you say or do because it could have serious consequences"?

Which proverb means "to be careful not to waste resources because they may be needed in the future"?

Which proverb means "to be patient and wait for the right moment"?

Which proverb means "you should not trust someone or something based only on appearances"?