Instructions
Press the "Start" button to access the main menu in "Pokemon Platinum." Select "Bag" and then "Key Items." Scroll until you find "PokeRadar" listed in the "Key Items" menu. Select it to equip the item.
Walk among patches of grass. Look for patches that are moving. If you immediately go to one of those spots, you will enter into a random encounter with a Pokemon. Equip Super Repels or Maximum Repels to ward off weaker Pokemon, which will increase the likelihood of encountering a shiny Pokemon. Enter every shaking patch of grass while using the PokeRadar and defeat the Pokemon you encounter to build up a chain of victories.
Defeat at least 40 Pokemon in random encounters resulting from shaky patches of grass to increase your likelihood of finding a shiny Pokemon. This process is referred to as "chaining." Chaining increases your odds of finding a shiny Pokemon from one in 8,192 to approximately one in 200.
Approach any rustling patch of grass that flashes immediately. These rustling patches of grass typically do not last as long as rustling patches of grass without flashes, so you must move quickly. If you reach the patch of grass in time, you will enter into a battle against a shiny Pokemon. Weaken the Pokemon through attacks and throw a Poke Ball to capture it.