5th gen Simple Guide to Grinding.
The best way to level up Pokemon? It really depends on the Pokemon & what you're going to use it for, as well as how much time you have on your hands.
The Day Care is a good leveling option for weak Pokemon, since each step you take is the equivalent of one experience point for both Pokemon in the daycare, made even better by the long route located near them, perfect for running or riding your bike back & forth. There's the slight hassle of ridding yourself of eggs if the Pokemon deposited happen to be in the same egg group. The big issue though is that Pokemon will still learn moves while they are in the daycare, automatically making said pokemon forget the first move in favor of a newer one. This takes an average amount of time.
Nice places to do this are Marvelous, & Skyarrow bridge, or for quick leveling, the route in front of the daycare.
Rare candying is a good way to raise Pokemon, since it requires minimal effort. They're also pretty hard to come by, so it's unlikely that you could raise them that way. I Black & White, Effort Values can still be gained & lost at level 100, so you could just get around to them later through use of medicine, wings or just battling. It should be use on higher leveled Pokemon, since they technically require more Exp to reach the next level. This is an extremely quick process.
Performed anywhere, really.
Battling against trainers will net some nice exp, while battling against wild Pokemon won't win you nearly as much. Slightly more Exp is rewarded if you are under the level of your opponent, though it wont matter much. Don't worry about Evs, they can be cleared through the use of berries, allowing you to start again. This may be time consuming.
Good places for this technique are the sports dome & the Elite-4 rematches, though being stuck in the E-4 can be an inconvenience to other tasks.
Audino grinding is a slightly costly way to level up. Audino award high amounts of Exp, but they can only be found in patches of shaking grass, where there is a 20% chance the Pokemon may not be Audino. Audino are relatively weak, making an gain, but keep in mind that it is a wild battle. Repels are often used with this, since Pokemon can interrupt you before reaching Audino's patch of grass. This may be time consuming.
Usually Audino grinding is done on Post game routes where Audino are higher leveled.
Tips: The Lucky Egg given to you by the professor boosts Exp 1.5 time.
Traded Pokemon also Receive 1.5 times boosted Exp.
Evolved Pokemon give almost double the Exp of unevolved Pokemon.
Chansey may very rarely be found with lucky eggs.
