Don't choose an old motorized piece of equipment that will look like a broken down vehicle. An object such as an old plow with flowers growing around it is a nice feature. Do not place it in the middle of the yard. Set it off to one side or place on the strip of land between your driveway and the neighbor's yard.
Use a large half-barrel flower pot and anchor it to the ground by burying it just under the surface or use spikes to hold it. Pour some dirt onto the ground and lead it back into the bucket. Plant flowers in the dirt. It will look as if the bucket was knocked over and the flowers are growing on their own. This can be used as a central feature.
This is the traditional fence of the midwestern prairie of the 19th and early 20th century. It is simply a fence post with logs used as the fencing. The logs are notched and fit in holes on the fence post. There are kits available at farm stores and some home stores. Normally the kits are used to make accent corners, but you can do a whole back yard with a couple of kits.
Using local wildflowers and grasses can also add a rustic look to the yard. If you do not know which flowers and grasses are native to your area, you can contact your local college, university or farm extension. Certain home stores or local nurseries will also carry these specific flowers. Some of these organizations will have fund raising sales in the spring where the plants can be purchased.