I think mastering the four tones should be anyone’s top priority when first studying Mandarin. I’ve seen lots of people struggle with this, because they haven’t taken the time to really get it right. It has meant that many times people don’t know what they are saying, purely because the tones matter that much to native Mandarin speakers.
I’d say the best way to improve the tones is to constantly mimick someone’s voice from a recording. Constantly play it to your ear, and then repeat it yourself. Keep doing this until you’re numb with how many times you’ve repeated a single word to yourself.
The more you drill this into your head, and the more you practice the four tones with different types of Mandarin words, the more clear your tones would be. Don’t skimp on this and don’t give up until it sounds almost identical to a native speakers pronunciation.