If you have noticed, almost all conditioners have the instruction “Take a coin size amount of the conditioner and spread through hair avoiding the roots” at the back of the bottle. Really?! Straight hair is so main stream that majority of conditioner brands forget that curly hair lives on conditioners. Conditioners do so much for curly hair. They hydrate, repair and very importantly – soften knots & help detangle curly hair. So yes, a coin size is more than enough when you detangling isn't a challenge!
Slip is the term used to refer to a coating to reduce friction between 2 hair strands. You know, something like a lubricant. Your hair should be soaked in conditioner so that there’s enough slip for you to detangle your hair and remove all the knots without damaging or breaking your hair. Without slip, the entwined hair strands can tighten further to become knots (picture combing your hair with a narrow toothed comb :P).
So the bottom line is to provide as much lubrication to our hair strands as it wants, to detangle smoothly. Each of your hair strands must be coated well in the conditioner. And by the end of your detangling process, your hair should feel soft to touch with all the tangles gone and the lubrication surrounding it. This will help you decide how much conditioner is the right amount for you to use. Start experimenting with half a palmful and go up if needed till you find an amount that works for you.
A palmful works best for me. A little less and the knots just sit there like a stubborn child. A little more and I am just wasting precious product and the shower floor gets slippery!