Bob_F_It said:
Using Mean Look might seem a good idea, but that means you have to stick around having a fight. There is an alternative if you find they keep using roost or are running out of PP (and strugling to death), and that is to walk back and forth between two different routes (so that the game keeps telling you) and watch the marking map, waiting for it to hit the same route you're on. Then encounter and lob a ball. Success is success, and failure means you just repeat.
As for making it easier to catch, if False Swipe is taking too much effort to work at first, kick it off with 5 or 6 Super Fangs, as False Swipe only kills a pokémon with 1HP. May seem obvious, but inflict sleep or paralysis (all freezing moves hurt).
You also wanted to know where you can get a double battle for sketching off of your own pokémon. You can go to the restaurunt on Valor lakefront, or there are a few trainers that will always fight in pairs; they're standing next to each other, instead of facing each other (the pair I always use is Ty and Sue on 209). What I did with my smeargle is a nasty secret.
That's weird. I found out about that strategy earlier today and waited until now to discuss it. Here goes:
1. Stock up on Ultra, Dusk, or Quick balls. Quick balls are advised for the birds while Dusk balls are sufficient for Mesprit and Cresselia. Ultra balls have half the chance of a capture comparatively. Get a group of Pokemon that has access to Hypnosis, Mean Look, False Swipe, and a low damage attack that is better than False Swipe. Put the one with Mean Look first. NOTE: All 4 abilities can be put on a Smeargle.
2. Go between 2 areas with grass that you can access and run between. Run between them until a wandering Pokemon enters the area you're in.
3. Use Mean Look on Mesprit and Cresselia. Then weaken them with the False Swipe and damage dealing move. Be careful not to kill it. NOTE: for this to work you need to use aa pokemon with Mean Look and False Swipe.
4. Hypnotize the pokemon when it gets to 1 hp (False Swipe won't do anything).
5. Spam Ultra Balls or Dusk Balls.
OR
7. If Zapdos, Articuno, or Moltres, Hypnotize them first (do not use Mean Look; in extended battles the bird will use Roost and destroy your progress).
8. The bird will run, but every time you meet it it will be asleep. Running doesn't give it a chance to awaken. Weaken it with False Swipe until it reaches 1 hp.
9. Spam Dusk, Quick, or Ultra balls. NOTE: This takes significantly longer than capturing Mesprit and Cresselia.
This may sound weird, but it does work. Caught all but Zapdos (because I switched to Darkrai and accidently killed it).