Summarize this article in one sentence.
To polish leather, you want to match the color of the polish to the color of the leather as closely as possible. Choose a neutral polish if you can't find one to match your Docs, or if your Docs are multicolored. Dr. Martens recommends using only wax-based polishes, and just on their smooth leather products. Choose a location that can get dirty if any accidents occur, and protect the surface you're working on with bags, newspaper, or some other cover. Take a rag or lint-free cloth and run it around in the polish in a circular motion to warm the wax, which will make the polish easier to apply. Apply the polish to the entire shoe, using gentle but firm pressure to get the polish into the leather’s pores. If necessary, use a cotton swab or soft-bristled toothbrush to get polish into the hard to reach places.  If your shoes are old and have never been polished, consider applying a second layer of polish.  When you're finished, allow the polish to sit on the shoes for 10 to 20 minutes. With a shoe brush, begin to gently buff and polish the leather all over, working the polish into the shoes and removing excess at the same time. If you're looking to achieve a mirror shine, the process is slightly more in depth:  Dip your finger into a pot of clean water and allow a couple drops to fall onto a spot on the leather. Dip a cloth into your shoe polish and rub that spot using circular motions. Work in small areas at a time, applying water and working more polish into the leather with a cloth. It will likely take a couple hours to cover the entire boot or shoe, but you should notice the leather getting increasingly smooth. When you’ve finished buffing your Docs with a brush or using the mirror shine technique, rub the leather with a clean piece of nylon to remove dust and extra polish, and to buff the leather to a shine. To give your Docs the longest life possible, clean and condition them every three months. To keep them looking as new as possible, polish them every time you clean and condition them.

Summary:
Find the right polish. Lay down newspaper. Apply the polish. Buff the leather. Shine the boots. Repeat every three months.