Summarize this article in one sentence.
If you've decided to build your own living wall, you may want to give it a test run before hanging it. Small mistakes in its lining can lead to dirt and water spreading to the load bearing wall your living wall is attached to. Prevent this by putting dirt in your wall before hanging and watering it. If leakage occurs, you may have to reline your living wall with plastic. You'll likely want to remove the dirt you used when testing before you actually install your living wall. The weight of the dirt can make it extra cumbersome when hanging. Depending on the size and weight of your pallet, you may need a helper to efficiently and safely install your living wall. Hold the back of your living wall so that it aligns with the dimensions you have previously drawn on the wall. Use a level to check that it isn't crooked. Then: Use your screwdriver and several suitable screws to anchor your living wall to the studs behind it. The kind of screws suitable for your project will depend on the size of your living wall. A larger pallet will require a sturdier screw to hold it in place. You should lay down a tarp or an old sheet to collect any dirt that falls on the floor. Take your potting soil and add it to the shelves/boxes of your new living wall. At this point you should also consider adding a controlled release fertilizer for your plants.  Controlled release fertilizers offer nourishment to plants over time, reducing the amount of continued fertilizing you'll need to do. As these fertilizers vary considerably from brand to brand, you should follow the directions that come with it carefully.  You may want to leave your sheet or tarp in place while adding plants to your living wall. However, if you intend on growing plants from seed, you should be fine removing your sheet or tarp, shaking the dirt on it free outside, and then putting it away. What you grow is up to you! But to give you some ideas, some of the most successful plants used by wall growers include the lipstick plant (aeschynanthus radicans), the sword fern (nephrolepis exaltata), wedding vine (stephanotis floribunda), and wax flower (hoya Carnosa).  You could create a mosaic looking living wall by growing succulents like Hens-and-Chicks (Sempervivum tectorum / Echeveria elegans), aloe, Panda Plants (Kalanchoe tomentosa), Christmas Cactus (Schlumbergera x buckleyi), and more. These will create a relatively low maintenance patchwork effect in your hanging garden. In mellower rooms, you may want to give a relaxed vibe. This can be accomplished with climbing and hanging vines. You might try Grape/Oakleaf Ivy, English Ivy, Philodendron, and Spider Plants. Without proper circulation, your plants will have difficulty purifying the air throughout your house. You can improve circulation very easily by adding a box fan or circulating fan to the room your living wall is in. This way, more air passes under the purifying touch of your living wall. You may find, especially during certain times of the year, that your living wall does not receive the same amount of lighting it did when your wall was built and hung. You don't need to install recessed lighting, though, for your plants to flourish! A simple lamp equipped with a grow light can help your plants make it through the gloomier times of the year. Grow lights are specially designed light bulbs that emit a kind of light that encourages plants to photosynthesize. Normal household light bulbs will not stimulate photosynthesis in the same way. How frequently you water and fertilize your plants will depend entirely on the kind of plants you have chosen to populate your living wall with. However, you should be aware that the resources normally available in nature won't be available to the plants in your living wall. Failing to water or fertilize can lead your plants to expire very quickly.

Summary:
Test your design. Install your living wall. Add soil to your living wall. Insert plants, or try to grow some from seeds. Improve circulation to receive the benefits of purer air. Add lighting to improve growing conditions for your wall. Water and fertilize your plants.