My neighbor taught me this trick after she purchased one of our Corten Steel planters. She uses empty plastic water bottles to fill up the planter about half way and then fills the planter up with dirt to the top.
This approach has several benefits:
1) The planter is not as heavy because half of it is filled with air that is inside the empty water bottles.
2) You can use less dirt to plant.
3) Plastic bottles at the bottom of the planter allow for excellent drainage.
4) Plastic bottles at the bottom of the planter promote air circulation and will help to keep the roots of your plant cool.
5) This is a great way to reuse the bottles which may otherwise end up in the trash.
Tip: make sure the water bottle caps are nice and tight on the bottles. Each bottle should act as an air bubble and keeping the caps tight helps ensure the bottles do not collapse under the weight of the dirt.
Say you are filling your planter box or flower pot with dirt on the deck or inside the house and you do not want dirt coming out from the drainage holes, but you still need the planter to drain. You can run to home depot and get some landscaping cloth (about $10). But why do that? Just line the bottom of your planter with newspaper or brown paper grocery bags. The paper will allow the water to drain while keeping the dirt from falling out. Also the paper will retain moisture, so less frequent watering needed.
I would stay away from using magazines, as all that paint on magazine pages will most likely prevent water from draining.
Our Corten Steel Planters are made to rust and will start showing the signs of rusting if you just put them outside for a couple of weeks and let Mother Nature take its course.
If you do not want to wait for a couple of weeks, wash the planter with warm water and soap when you first receive it. This will remove any remnants of oil and the water will react with the metal initiating oxidation (rusting). A periodic mist of water will accelerate the oxidation process, especially if you are in a dry climate.
Spraying vinegar onto the planter will give it the rust look in a matter of minutes. This rust however washes off, so the next time it rains, your rust will be gone. The planter really just needs a few months, with or without vinegar, to gain a natural layer of rust and seal.