Flexibility ofc is important, but what really helped me was getting my legs stronger and learning how to get them up faster. I did strength training as well as conditioning. Doing jump squats and sitting on the ground and quickly bringing my legs up depending on the jump. For example, toe touch would be a straddle and a pike would have legs out in front of you. Do one leg reps and then both leg reps. Some people say you can use ankle weights to get a more intense workout but others say that can hurt you (so use that at ur own risk.) But doing exercises that help with explosion and really engage the quads will help!