Teaching tones in Mandarin is extremely important. I like to introduce the idea of tones to students as early as possible so they have the framework to listen.
Use hand motions to teach the tones. Students use their arms as arrows with their hands pointing in the direction their voice should go.
Listen and Respond. Have students listen to tones and hold up the tone they hear on their fingers.
If students are looking at others students answers, have students put the answer “in their fist” and hold it up only when you say “go” or “一，二，三…”
For older students, Pear Deck is a great way to engage students and helps them visualize the tones. Check out this interactive Pear Deck on TPT:
Tones Bingo is a great way to get students listening. Create a 4×5 table and label the headings 1st, 2nd, 3rd, and 4th tone. Give students a list of words to fill out for each tone. Call out one of the words on the list and check students understanding.