both have three sounds they both start with  k and they both end with f the difference  

is the vowel in cuff I have a very relaxed  mouth and that short uh cuff cuff cuff for cough  

my mouth is open wide like you're coughing open  in a wide oval shape tip of the time is low  

back of the tongue is pulled high up cough cough  cough cuff cough cuff cough cuff cough cuff  

cough cough cough i try to cough into the  cuff of my shirt to be polite give it a try