Improved experience training

Introduction
When it comes to leveling up, there are only two ways: grinding (e.g. battling opponent after opponent for a really long time to gain exp and eventually level up) or rare candies (duh). If you're reading this, I'm going to assume you don't have the resources (money, charisma, etc) to amass rare candies and are here to figure out "what is the best method of grinding". To which I say: you've come to the right place my friend.

What to Grind
Generally speaking, you will want to grind against enemies that are a few levels (2-5) below your own. This is usually the case when you don't have an advantage over your opponent.

For Example:

Trying to level up a Rattata at Mt Moon. Rattata has no advantage over any of its opponents, so it's beneficial to have it fight lower leveled opponents. The exception to this rule is if you have a Pokemon with an advantage over its opponent, such as grinding with a Wartortle at Diglett's Cave/ KantoConnex the only thing you'll find are Diglett in certain areas and I'm pretty sure your Wartortle knows a water type move (it should).

Where to Grind
When grinding, take into account Effort Values(EV's). This might lead you to, for example, train your Pichu at Mt. Moon. You're having fun at first, shocking Zubats away when - uh oh! It's a Geodude! If you've ever raised a Pichu (if not, don't. It's generally hard) you'll know it only learns an electric attack, which has no effect on the rock/ground type Geodude. The fact is, you'll be forced to switch, and as you probably know that halfs exp as it gets split between combatants. To make an overly long story short and as a simpler version for all those of you who pulled a tl;dr on me: location is VERY important for grinding. As a general rule, you'll want to maximize Exp gain by 1-shotting highish level enemies while taking no damage in the process. A good example of this is, again, Wartortle at Diglett's Cave.

Weak Pokemon
Here we are at the final point, which is incidentally the hardest point to accept. When you catch a new Pokemon, it's a wuss (or you bought a Pichu cheap, RIP my soul). You'll likely have to do the method where you have it up front, switch it, and beat the enemy with a Pokemon far better leveled. But that's ok. It's better to let it gain exp than have it faint and be forced to go to the Pokemon Center (which is generally kinda far, and you might not have a bike).

FAQs
1. If a Pokemon faints it will get exp from that battle, but it can not gain exp until revived after that.

2. You can not gain exp from player vs player battles (sucks, I know).

3. Grinding takes a while. Even with these fundamentals, it's still a pain that takes a while.

Thank you for reading

Credits
Formatted by: iPuggo

Notes: First of all, I wrote this on my phone. Not only should you feel free to format this article, I'm actually on my knees begging you to make it more visually appealing. Secondly, there are no sources I can give other than "I have played every Pokemon game since gen 4 diamond" and "I win battles by doing the math ahead of time." That said, this article is entirely subjective to my experience of playing Pokemon Planet. If you feel you have found a different, more streamlined, or overall better method, by all means please let me know with a message.