The knack of doing Uchimizu is to sprinkle, in the morning or evening when air temperature is low, water stored in a bucket little by little on the ground or the wall of a house.
打ち水のコツとしては、朝夕の涼しい時間帯に地面や家の壁などに、バケツなどにためた水を少量ずつ撒くのが良い。