How to get more height on an aerial cartwheel?

I'm a Level 8 gymnast too and i'v had lots of trouble with Arials too. you could probably use more height, but i'm thinking that fear may be an issue too... My problem is i'm afraid of the sideways landing, so i always put my hand down to control it, and feel safer. It helps to be spotted on it a few times before you try it by yourself and it will make you feel more confident. but if fear is not the issue, there are drills for them too. if you guys have a wedge (hill), do them going off the end by running to and up the hill and landing on the floor, which will help make sure you have enough height. you could also try doing them into a foam pit (or resee pit) until you have the height and timing and skill down. once you can do it good into the pit, try putting an 8incher into the pit and doing them onto that. its a softer landing and you wont have to worry about your landing as much as floor, but it will show you where the landing is. also ask one of your coaches to spot you on the floor. finally, we do a drill called a dive-cartwheel that is basically an Arial but with hands. you hurdle or jump into it but you also put your hands down at the last second. once you master that, try only putting one hand down. good luck!