Box breathing, also known as square breathing, is a technique used when taking slow, deep breaths. It can heighten performance and concentration while also being a powerful stress reliever. STEP 1: Inhale slowly and deeply through your nose to the count of four. In this step, count to four very slowly in your head. STEP 2: Hold your breath for another slow count of four for 4 sec. STEP 3: Exhale through your mouth for the same slow count of four, expelling the air from your lungs and abdomen. STEP 4: Hold your breath for another slow count of four for 4 sec.