Landfills are expanding everyday, and so are trashes. Between 1960 and 1990, trash production has doubled, and since then remains at about 4.5 pounds per person per day^[1]^[2]. We're seeing an ever increasing need to recycle and reuse, but to really eliminate the problem we must not try to correct the symptoms but the disease. Consuming intelligently and putting pressure on companies to use biodegradable and recyclable material without overwrapping their products is one of the best solution.

[edit] Steps

Do not buy overpacked products.
1. Ask your butcher to wrap your meat in peach paper only, then attach the price on top to keep the paper folded. Peach paper is a strong, water and oil proof, beef or pork wraping paper normally used to split stages of meat inside a styrofoam cup. It is available in rolls or in sheet.
2. Buy fresh, unpacked, fruits and vegetables.
3. Use your own bags when you go grocery shopping -- both paper and plastic bags are doing little good to the environment.
4. Demand that store clerk doesn't put certain items that have their own handles (milk bottles, laundry detergent bottles, etc.) into the bags -- they're probably more convenient to carry by that handle.
5. It is usually beneficial to pack your purchases yourself: you can choose what to put where, nearly always in a more convenient way than the clerk does, and you don't have to stand there bored out of your mind waiting for your stuff to be packed.
Go Paperless! Paper constitutes about 30% of average American's garbage^[3].
Give (freecycle.org) or sell what you don't need.
Reuse and Recycle!
If you own a home, you are likely putting your yard waste (leaves, tree branches, etc.) into trash -- and that makes up to 15% of it^[4]. DON'T! Let's take a little biology detour: trees are composed not only of carbon they capture from the atmosphere (in the form of carbon dioxide) but also from other chemical elements they draw from the soil. In the wild, the fallen leaves decompose over the winter, not only protecting the soil (and plants' roots in it) from low temperatures, but also returning those elements to it. If you collect the leaves and dump them, you're routinely depriving the soil of these essential elements as they're hauled away in the trash, and now you have to buy fertilizers to compensate! Let the nature have its way, or, if you think that fallen leaves are unsightly, make your own fertilizer: collect, shred and compost them, and spread the compost over your lawn the following spring.