which ever conditioner you use, leave it on your hair for 5-7 minutes before you wash it down.
also, try using some kind of hair oil, like moroccan oil or coconut oil and apply it warm and keep it for about an hour and shampoo and condition as you would like.
since you want a natural way,
for shiny hair: use lemon juice once a week on your hair.
mix half a lemon juice with same amount of water and pour it down on your hair and run you finger through your hair for a minute or two just to take the time for it to reach all the parts of your hairs. and wash it down.