First and foremost, any kind of simple garden plot imparts a degree of frugality if it remains just that–simple. What could be easier than a small salad garden. Greens, a few herbs like chives, parsley, basil, and dill, and, one or two tomato and green pepper plants saves money, gasoline, and time.
Using the cliche of the moment, “take it to the next level:” a pair of 4′ x 8′ raised vegetable beds will produce plenty of fresh produce for the table. You can’t get more organic or locally grown than your own yard. Plus the flavor factor–taste a fresh carrot pulled from the ground 10 minutes before it hits the vinegar and oil vs one wrapped in an orange plastic bag. See instructions at: https://coco724.wordpress.com/2008/04/11/construct-a-raised-vegetable-bed/
Fish pond in your garden? Once in a while scoop a bucket into the pond, using the water to give your plants an inexpensive and organic nutritional boost.
Save your personal energy and time. Stash a covered bucket in an unobtrusive spot in your landscape to store small hand tools. How many times have you walked to the garage or shed to get the hand pruners?
Talk to your neighbors about sharing a truckload of mulch, gravel, sand, cement, or whatever else can be shared in bulk. Be smart about it. Pick your partners wisely, agreeing to some common sense rules in advance. Collect the money first–no money, no mulch. Pick a common time to distribute the material, deciding ahead of time how to divide the material. For example: use the same wheelbarrow to dump alternating loads among all who chipped in. Side benefit? How many plastic bagfuls does it take to fill a dumptruck?