Less is more when it comes to cleaning detergents.
For a while I had a lovely friend help me clean the house for two hours a week. The place always smelled beautiful when she had finished. I just found that she would happily go through a bottle of general cleaner and another bottle of floor cleaner a month, I could hardly keep up with buying more and more of the stuff. Now that I am staying at home with the children, I do everything myself and I find that I use far less. In fact, I haven't bought any chemical cleaners since.
Simple baking soda makes a great cleaner for cook tops and for general cleaning purposes.
Vinegar is an effective cleaner for floors and surfaces.
We try to use the minimum possible amount of dishwashing and washing powder.
I find that dishwashing detergents tend to be far too concentrated. However, we are all used to putting a good squirt of detergent into the dishwashing water and it seemed just too hard to re-educate everybody in the family and change our bad habits. Now I water down our dishwashing detergent by dividing it between two detergent containers and filling the remainder up with water.
Plastic bags, including freezer bags, get washed and reused until they fall apart.