After an extra long absence, I'm considering trying Pearl version once more! Of course, there is still much preparation to be done, and I might consider preforming a FireRed run instead. Until then, here are some tips when trying to Locke' Black and White version:
1.)
The daycare is your FRIEND! Next time, when you get a pokémon that you think you don't need and want to box it, put it in the Daycare instead, so in the case that a vital team member has fallen, you'll have a tough new member to add to the fold! The fact that Unova is riddled with extra bridges helps.
2.)
Lucky Egg! Assuming that you haven't locked the use for items entirely, the egg will cut grinding in half, thus reducing the amount of potential casualties from critical encounters. You're going to have to grind a lot if you want to have a balanced team!
3.)
Evolite will make all those mid-staged members of yours much more likely to survive the long haul in order to make it to their powerful final forms! This is great for Klang and Krokorok, who'll see quite some down time between their middle stage and final forms.
4.)
If your going for defeating Cynthia in order to complete your challenge, the post-N game is hard. Make sure that your primary poké is at least 65 before challenging some of the later trainers.
5.)
Audinos make great EXP. fodder. Search for them early and often to swiftly boost your level gain!
6.)
The Liberty Pass! Though Victini itself might not be allowed for use, the extra trainers you get access to will provide vital extra experience! Might also give something interesting to add to your story.
7.)
Nurses and Doctors make grinding much easier, and providing your not putting restrictions on them, it's never a bad thing to ask one of these field medics to patch up a poké who seems like it "Could take a couple more blows." You'll thank them later when your Pokémon is still standing after "Critical Hit!" shows up.
8.)
Unless you're extremely careful, you're going to lose some team members, be it from those dastardly Emolga, Watchog's Retaliation, having the snot beaten out of them from trying to capture Throh/Sawk, or many other, less noted methods involving critical hits. Before you have your final team decided, catch anything you can, even if it's one of those worthless Patrats! These willing pokémon will give their life as cannon fodder in order to assure that your tougher members live on. Sturdy stuff like Roggenrola will always survive a single blow, so their efforts will never go to waste trying to heal your team! Rock on little Rog, rock on...
9.)
One more thing! The Excadrills in Victory Road know Horn Drill! Stay clear of these mighty foes unless you're of a higher level then them!