There are times when the item you need to abrasive blast cannot be moved into an industrial blasting booth for one reason or another. If this happens, you have to prepare an abrasive blasting area where you'll be able to achieve a good result with minimum environmental contamination.
Also, you have to think about people in the vicinity to make sure there are no health risks and that the noise will not be a problem in built-up areas.
The best results will be possible indoors, where the abrasive blasted surface can be kept clean until a protective coating can be applied. (Note that this ideally has to be done within four hours of the abrasive blasting, otherwise corrosion will start forming on the metal.)
Close off the space as much as you can, using tarpaulin covers or plastic sheets where needed. You may also want to hang "curtains" to contain the blast material. Despite your best efforts, you have to be prepared to clean up a lot of dust afterwards. Sweep the area carefully after each abrasive blasting session. If you strain all the dust you swept up through a fine mesh screen, you will probably be able to recycle the blast medium for later use. If you use a commercial abrasive blasting outfit, they'll probably do this themselves.
In the outdoors, you should still try to find the most protected area possible if you have the choice to do so – even just a roof helps. Where possible, erect temporary skirts to contain the blast medium. Working on a hard floor helps to make it easy to sweep up the used material for possible reuse and to prevent it finding its way into the environment.
In order to protect the environment, it's best to use only abrasive blasting media that are environmentally friendly such as garnets, coconut shells and the like. Using sand is not a good idea, as it contains silica which you might inhale, causing lung disease.
Wherever the abrasive blasting is done, try to keep the surface of the blasted metal clean by wiping or blowing the dust away and covering it up where possible.