A simple tip she gave was to use less of everything-detergent, shampoo, cleaners, etc. The instructions for most products tell us that we need more than we actually do to get the job done. It is possible that the companies have a financial incentive for us to use more of their product.
Here is how you do it: First pour out the amount of detergent you usually use and make note of how much that is. Then, the next day, decrease by a little and see if the clothes still get clean. If so, then decrease a bit more the next time. Keep doing this until the clothes are not cleaned well and then back up to the previous amount. This gives you the minimal amount needed to do the job. It is actually amazing how much less you need of many things. Doing this made me wonder how I had settled on the started volume to begin with (not being a much of a direction-reader). I find that I need to do this again periodically as the amounts start creeping back up when I am not paying attention.
Hardcore "greenies" will question whether this is really a green tip if you are still using toxic chemicals. Yes, that would likely be better, but this is a good start for those who are really attached to their detergent and are unlikely to make the switch. If everyone did this for all their products, it would mean less chemicals produced and used, less plastic (containers) and less trips to the store to restock. How low can you go?????