my hair changes everytime i wash it. sometimes it needs a little sometimes lots. thing is when i first smooth conditioner over my hair it feels like its totally been absorbed into my hair. but when i comb it through i can really see how much has been absorbed. it usually sits on top so i can see why stuff on my hair but a minute later will be gone - voila its been drunk up by my hair! so i'll apply a little more (2 pea sizes worth) and then wait a minute. if its gone i'll apply more until my hair feels seaweedy and looks really shiney. if i keep applying unitl i can see conditioner on my hair that isnt absorbed then i have overconditioned. so i dont put enough on that i can see the conditioner on my hair without it being absorbed, i apply enough that its all absorbed and feels really seaweedy.
Hope that made sense! its a fine line but once you crack it your hair will love you