Use cloth diapers if at all possible. They are much cheaper and better for the environment.
Sales, special offers and freebies
Free stuff can be okay but one should watch for the reason why something is free. Some trash is truely another man's treasure but not always. There is a carrying cost to having stuff so one should see how much utility to cost they would get from cheap stuff.
Some used goods can be really good. Baby clothes should all be bought used as they'll be useless in a few months anyway. Electronics get upgraded so quickly that only the richest can keep up. Buy used computers at reputable stores and keep them until they break. Then "upgrade" to the next model. Computers should not cost more than 150-200 US$/year.
Internet and technology
Use e-mail rather than the phone to keep in touch with relatives and friends... Especially overseas ones. Use tools like Facebook and MSN to keep in touch with co-workers and associates reducing unnecessary meetings and trips for get togethers. Don't fool around with e-mail attachments and dirty sites that will infect your computer and require replacement. Get rid of your cell phone and only conduct your business online or face to face. This will increase professionalism and take out a lot of stress from your life. For personal uses you can have free software, many of them are as good or even better than the so called paid software-Linux/Openoffice.org/Firefox/Evolution are some of such solutions.
Energy prices are increasing. Walk more. Use your bicycle to cut fuel costs. Use a fan instead of the air conditioning. Put on sweaters instead of turning up the heating or do some stomach crunches to warm up. Always turn off the lights when you leave a room. Get a library card instead of watching television.
Reuse and recycle
Old clothes can become rags. Milk containers can become cutting boards. Misprinted material can become fax paper.