1. A container to hold the soap. You could easily reuse some sort of cardboard box or tub. I thought this cheap container would make it easier by being able to pour out the powder. I was wrong, it isn't very feasible to pour out and measure one tablespoon... I wish I had gone with a pretty jar and scoop instead.
2. Some sort of scoop to measure and mix the soap. I just use a tablespoon measuring spoon out of my kitchen drawer. It was a good excuse to buy a new set. :) Now I just keep the old spoon right on the shelf with the container.
3. Washing soda (not baking soda, though it is a form of baking soda) which softens water and helps remove stains.
4. Bar soap (I used Fels Naptha which is a laundry soap but you can use any bar soap such as the Ivory pictured here which is going in my next batch). You could even choose a scented bar if you would like. I beleive that true clean has no smell, but there are some pretty fresh scents out there...
5. Borax (removes stains similar to oxyclean).
I bought all of this a while back, but I am pretty sure it cost under $10. I only use about one teaspoon per load in my HE front loader, and we have soft water. For hard water or regular machine you might need more.
All you do is grate ONE BAR of soap (I use a cheese grater but you can use a food processer), add ONE CUP washing soda and ONE CUP borax. Mix very well. I usually stir before each use, as the soap flakes tend to separate out. This is what it looks like.
That's it! I have seen recipes where you can other things like oxyclean, fabric softener beads, and baking soda. I prefer to add these separately as needed. I have been using this for several months, and it works great! I give it a 4/5 because it does have one major drawback.
*Despite claims that it is safe, this did NOT work for my cloth diapers!*. It left.a coating on the suedecloth inners and caused major repelling/leaks. I had to strip my diapers and am now having good luck with original Tide. I use the home made stuff in the rest of my laundry, though and no complaints. It hasn't irritated my daughters super sensitive skin at all.
I plan to blog more about cloth diapers, feel free to ask me questions.
Now, go make yourself some super easy, super cheap, effective laundry soap.