Grip on by your dominant hand.
You can also grip the handhold with you palm facing up, or by an over grip with the palm facing down .make sure you have a good grip.
Emphasis on squeezing by your thighs.
Too many people think the control is on the one hand you are holding on with. You would be using your leg muscles to “root” you to the bull.
Relax your upper body.
The ride operator is going to try and use your upper body weight against you after the bull bows down in front and the rear tips up.
Your greatest strategy is to point your heels together and try to lean back once the bull dives frontward to counter the force and then rhythmically change your weight the opposite way when the bull tips up in the front.
Use your free hand for stability/Balance
Think, how a tightrope walker use their hands to uphold balance you would be doing similar with your free hand. Though it might look like people wave it around just to look cool, it actually can relief you stay on the bull.
Shift your weight
At times, the operator will make the bull go up, down, left, right and circles. Shifting your weight will help.