You will need:
> one empty bottle of dishwashing liquid;
> one bottle of dishwashing liquid (your favourite);
> one bottle of white vinegar (I use the cheapest I can find)
> tap water.
Detailed instructions in next step ...
Step 1: Instructions
1. Fill the empty diswashing liquid bottle with:
> 1/3 dishwashing liquid (your favourite);
> 1/3 vinegar;
> 1/3 water.
2. Close and shake (don't stir). It's ready to use!
Comments and tips in the next step ...
Step 2: Comments and tips
Very good for areas with hard water - the vinegar dissolves any scale.
You can add less vinegar if the water in your area is soft.
I usually have three identical empty bottles on hand to make some stock.
You'll spend less and wash less dishwashing liquid down the drain for Mother Nature to deal with.