Here are some things you should be aware of before attempting to chain Pokémon:
- Your chain will break if you use your Bicycle or Roller Skates.
- The PokéRadar cannot be used in the Friend Safari
- If you leave the field of grass, your chain will break
- Buy Repels. Lots of them. This is important, you don't won't to encounter a random wild Pokémon in the grass when heading toward a patch. I usually prepare about 200 Max Repels, but recommend more to be safe.
- Make sure there are no eggs in your party. If an egg hatches while you are chaining, it will break the chain.
- Have a high level Pokémon. Makes the process faster.
- Turn of battle animations, it speeds things up a lot.
- Bring Ethers. You don't want to run out of PP.
- Relax. Don't do this when you're annoyed or angry, you'll most likely end up with a broken 3DS when your chain breaks at 39.
Step 1. Choose a patch of grass. Preferably a large one, about 5x5, but one where you can see easily from an above angle.
Step 2. Use a Repel
Step 3. Start the chain. Once you encounter the Pokémon you want to chain, you can either defeat it or catch it to continue the chain. It is best to start your chain in the middle of the field.
Step 4. Continue the chain. After the first manual shake, another few patches of grass will shake. Walk in to one of them. Picking the appropriate patch is important. Remember the nature of the shaking of the first patch. Was it soft shaking? Or hard shaking? Pick the one that shakes the most like the first patch. Do not walk in to patches that are directly diagonal or adjacent to you. They are most likely to break your chain, and try to avoid patches on the edge of the field. If you don't see any patches that seem appropriate, simply reset the PokéRadar until you find one that does. The act of resetting your PokéRadar is simply manually using the PokéRadar again, and does not break your chain.
Step 5. Keep repeating step 4 until you get to a chain of 40. Remember to record the amount of chains. The. Move to step 6.
Step 6. Once you reach 40 chains, the shiny rate will increase no further. So once you reach 40 chains, simply keep resetting the PokéRadar until you see a sparkling patch. This patch contains a shiny. Don't forget PokéBalls.