Ok so first you need to buy:
1 Fels Naptha soap bar (Wal Mart has these for $1- you will need to buy 1 every time you make a new batch)
1 Cup Washing Soda (it comes in a big box so will last you through a few batches)
1/2 C Borax (also will last a while)
First thing you need to do it grate the soap bar into a saucepan and then cover it with hot water. Cook over medium-low heat, stirring the whole time, until the soap dissolves all the way.
Put the washing soda and borax into your 5 gallon bucket.
I got my bucket at a yard sale for fifty cents, but you can buy one at Lowe's or Home Depot for a few dollars. Pour in the hot, melted soap mixture. Stir well till everything is dissolved. Then fill the bucket to the top with more hot tap water. I leave the bucket in one side of my sink while I fill it up and leave it there until I remove about half of it to put into soap containers because otherwise its too heavy for me to lift.
So after you have filled it all the way up with hot tap water you let it sit like that with the lid on overnight. The next day stir the mixture good. I actually wear a tank top and put my whole arm in to stir it up and break up all the gel really good. Then you can mix equal amounts of the mixture with water in a smaller laundry soap holder. I use a funnel and a Pyrex measuring cup that holds 2 cups..i pour 2 cups of soap mixture, then 2 cups of water alternating till my container is full. When I am doing laundry I give the container a really good shake before pouring the soap to break up the gel a bit.
For a front loading machine, use 1/3 cup of soap per load.
For a top loading machine, use 1 cup of soap per load.
Good Luck and Happy laundry doing!!!