OT- anyone make your own laundry detergent?

ok, i am trying to wrap my brain around this idea...how much of the made stuff do you put in the washer when you use it? like the cups that come with the tide or what ever? did you dissolve the bar soap in a very large pot of about how much water? and how much eucatlypt oil did you add...and last one...arm and hammer washing soap...never heard of it..borax, yes i have seen that and used it..but not the other...and i have alarge jug of ERA now so will keep my jug to refill for later on...
thanks for the tips..
debby

The instructions I have say to use about a cup in a load of laundry but I will try it with a little less and see how it works.

I dissolved the soap in a pretty big pot of boiling water.  Um, I don't know how big.  It's the pot I make pasta in, or soup, stuff like that.  I don't think you need to be precise about that one.

I put in 15 drops of eucalyptus essential oil, because a little goes a long way.  But the smell is pretty overpowered by the soap smell now so I might add some more.  For comparison, though, you would only add about eight to ten drops of essential oil to a whole bathtub of water to bathe in.

The arm and  hammer washing soda (soda, not soap) was right next to the borax at my grocery store.  In a box just a little bit bigger than the borax.

 I used this recipe for about a year.  I thought it worked as well as cheap detergent (Purex), but my husband made me stop using it because he said he couldn't stand his whites being gray anymore.  Now we use Tide, and it works great.