There are a couple of useful things to have in your kit to heighten safety for the most part when starting to practice outside of the comfort zone of an ACRO course.
Altiude awareness -
1. Flight logs: recording heightloss during tricks.
Flyskyhy app for iphones only. Using graph.
Enabling you work out height loss with every trick and measures sink rates.
2. Live altitude reading - A smart watch 360° Moto sport with app called “smart altimeter”
Shows altiude and sink rate. Is handy and small in a watch form.
3. Last but definitely not least. An audible altiude warning alarm. Fitted in helmet, custom alarm altiudes.
eg. Alarm 1 at 300mtrs a couple of beeps. (Time to look at exiting.) Alarm 2. 150mtrs. Stop all tricks. Trouble? deploy! Alarm 3. 70mtrs. Very last chance to cutaway or reserve.