Exactly how and when to use oil on the hair

I've never used oil on the ends of my hair. However, it's getting longer (yay!), and the hair is getting older.

For those who "oil" the ends of your hair -- how far up do you apply the oil?

How often do you apply the oil?

How much do you use -- enough to completely saturate the hair or just enough to "skim" the surface?

I have a normal to oily scalp, so I'm certainly not getting any oil close to the scalp, but I'd like to try to apply some oil on the ends.

Thanks.

Yeah, I put oil on from the ends down. I probably use too much. I'm in that bad habit. I do that once or twice a week, or whenever it feels crispy.

But sometimes I use jojoba oil as a leave in conditioner. I think Grenwich recommended that to me awhile back. Then I just use a pea-sized amount and smooth it all over my hands before I run my hands through my hair.