Leveling up your Pokémon is the single most crucial part of the game so it’s important to understand that Black & White have made some noteworthy tweaks to an otherwise simple concept.
When your Pokémon defeats a rival creature the exp reward is worked out depending on the Level of the combatants. If a Level 10 Pokémon defeats a Level 15 Pokémon, for instance, it will gain substantially more experience points than if a Level 20 Pokémon did the deed.
Make sure to use lower Level Pokémon as often as possible as if you focus on one high Level Pokémon then you will be compromising your potential experience gain and the game will become harder.
HM slave freedom
A vital tip before you lumber a potential party Pokémon with a ton of HMs. Unlike previous titles you only ever need Cut once for the entire game.
Similarly, the other HMs are only ever needed for optional areas or during the postgame. So don’t feel forced to carry a HM slave with you at all times.
TMs, or ‘Technical Machines’, were previously one-use items. However in Pokémon Black & White you’re free to use them as many times as you want, so go crazy!
Many TMs hold special moves that can seriously boost your abilities and thanks to the fact you no longer need to stockpile them you no longer need to keep thinking ‘but I might want this later…’
The Exp. Share is found in Castelia City's Battle Company building, top floor, after beating the chap in the corner. Giving it to an underlevelled creature and defeating high-leveled opponents will help boost an underlevelled creature with no hassle.
As tempting as it is to walk through the game with your powerful Legendary creatures bulking out your party, prestigious area such as the Battle Subway do not let you use them, while friends will likely roll their eyes and sigh when you send out your powered up Reshiram or Zekrom.
If you focus on using more basic Pokémon you will be able to access more of the game, and find more respect from your peers. That said, if your main aim is to blitz the main story, by all means use them!