Start at 150ft... Close your eyes and wank on the sticks... Now open... Try to recover... If you make it, start at 140ft and try again.... Continue this process until you crash.. Then you've found your "1 mistake" height... Simply multiply this length by the number of mistakes you wish to be high... i.e. If your 1 mistake height is 30ft, then to get 3 mistakes high you would need to have an altitude of 90ft. Please be aware however, some conditions will require an adjustment to your 1 mistake high altitude... Cloudy days for example, can add 20, 30, or sometimes even 50 feet to your 1 mistake altitude... Any time the conditions are different (wind, clouds, rain, area, etc...) you want to make sure you repeat the testing procedure to find your ideal height for those conditions...