I've tried to stop buying so much coffee when I'm out - I take a bamboo cup with coffee in from home or my thermos flask when I go to the park. Yes it saves money, but it also saves on buying coffee in disposable cups. I'm making an effort to do this with cold drinks too - I carry a reusable bottle full of water with me rather than buying water in plastic bottles when I'm out.
In the house I'm looking at our plastic consumption and I'm thinking I'm going to move over to making soaps - hair soaps, body soaps, laundry soaps - I already use french olive oil soap for cleaning and laundry stains and it is very cost effective. I just look at the amount of plastic bottles in my bathroom and kitchen and I think could this be replaced with a few bars of soap?

I know your post is about being more frugal, but from approaching things from the angle of reducing waste I seem to be saving money too!