From Longman Dictionary of Contemporary Englishmake up your mind/make your mind upmake up your mind/make your mind upa) DECIDEto decide which of two or more choices you want, especially after thinking for a long time I wish he’d hurry up and make his mind up.make up your mind/make your mind up about He couldn’t make up his mind about what to do with the money.make up your mind whether Karen couldn’t make up her mind whether to apply for membership or not. b) DECIDEto become very determined to do something, so that you will not change your decision No more argument. My mind is made up.make up your mind to do something He had clearly made up his mind to end the affair.make up your mind that I made up my mind there and then that I would never get married. c) to decide what your opinion is about someone or somethingmake up your mind/make your mind up about I could never really make my mind up about him. You’re old enough to make your own mind up about smoking. → mind
Examples from the Corpus
make ... own mind up• They would be able to read the newspapers and make their own minds up about the corruption and deception going on.• I made my own mind up.• You will just have to make your own mind up on my views. 