That last stretch....

[ISA56 2.0]

Thankfully, I no longer have this problem due to my obession of "overleveling" mah Pokeymanz, mostly to level 70. However, I used to have this problem all the time when I was newbie at Pokemon (and RPGs in general) because I thought I could just breeze through the Pokemon League with a single level 40 Pikachu. How wrong I was. How wrong I was....

 

[CptSwaggerPants]

I just keep going up against the elite four until I can take them and beat the champion, I battle them, lose and heal and then battle them again and soon enough I've gained enough experience to become champion. I don't use any items during this process because when it comes time to finally take them all on I need to stock up on full restores, full heals and revives.

This is exactly what I do, usually training one Pokemon at a time though.

 

[レイジングブラスト]

I don't know why but I always feel underleved when I get to Victory Road and end up having no choice but to train and even after that the e4 levels are still higher than mine.

 

[Rai]

When I first get to the Elite Four, I usually do a test run of it with no intention of winning. I like to see what kind of pokemon I'm going to be up against and what their levels are (I don't like looking up them up beforehand). If I happen to win that's awesome :D If I don't win, I train until my pokemon are at the right level and then stock up on potion.