You can create a range of garden ornaments with cement and junk. A sand-cast bird bath dish is a fun and easy project that involves molding wet cement over a mound of wet sand covered in plastic. Or add decorative stones to wet cement and mold it over small plastic bowls to make patio candle holders. Mold cement around old tin cans to make deep patio or garden candle holders. Push wire handles into them to hang them on shepherd's hooks or tree branches. Consider making a bird house. Mold wet cement around an inflated balloon, pop the balloon when the cement's dry, and hang your creation from a tree branch. Rubber gloves and cement mold-release spray make the work easier and neater: Wear gloves to mold the cement, and spray the molds before covering them with cement.
Create a colorful bottle tree to decorate the garden. Search for a fallen sapling with a lot of branches, or use a 5-foot-2 post, pushing the bottom end into the ground or anchoring it in a utility bucket filled with rocks or gravel. Drill holes at angles so that dowels inserted in them will sit at upward angles like tree branches. Place bottles on the ends of the branches or dowels.
Create fun fountains from junk and a small submersible water pump. String old pots and pans together with galvanized wire, and layer them so that water can fall from one to another, finally splashing into a basin at the bottom. Use old clay pots in a similar way, with a large pan or plastic liner tray at the bottom and overturned clay pots as pedestals for water to flow over. Be creative with your fountain, and use junk you have or find at garage sales or flea markets to create your own ornamental garden fountain.
Create beautiful garden ornaments with mosaics. Break up old clay pottery, and set the pieces in wet cement that will be used as stepping stones when they're dry. Break up bathroom or kitchen tiles and arrange them on a tabletop. Cement and grout them in place.
Make a fluttering wind ornament in your vegetable garden, and keep the birds and bunnies away. Cut out whimsical shapes from disposable aluminum baking pans, such as stars, moons, flowers and hearts. Hang them from a wire coat hanger with string or wire. Hang the finished decoration on a shepherd's hook in the garden or on a nearby tree branch so the shapes move in the wind, creating noise and movement to startle the birds and rabbits. Junk silverware, small plastic toys or any lightweight knick-knacks also work for this project.