Learning Japanese really isn’t that difficult. Hiragana and Katakana can be learned in a day, speaking comes from having Japanese friends… but then there’s kanji. Kanji is perhaps the (seemingly) most difficult aspect of the language. There are several ways of making Kanji-learning easier.
The traditional way of learning kanji—repeated writing until it is etched into your brain—is a simple, but boring and somewhat inefficient method of kanji memorization. This method is only really good in the beginning, when you are first learning how to properly write kanji, that is, where the strokes go, how to write quickly, etc. Most people will have to go through this initial phase since it is important to have a type of kanji-writing muscle memory.
Having learned the basics though, other methods may be introduced to complement your learning: Kanji radicals (the building blocks of kanji) and mnemonics. Learning the radicals is very important; this way, even if you do not know the meaning of a kanji, you’ll still have a rough idea of it. For example, the kanji for “rest” is made of two radicals: person (亻) and tree (木). To remember it, we add a little bit of mnemonics: “The person resting by the tree (休).”
Remembering the Japanese readings requires a bit more effort of course. Again, there is rote memorization. If you are in Japan, this will usually suffice since you’ll be seeing kanji just about everywhere—after all, the best way to learn how to read is to read. There are websites and apps for more systematic learning, of course. Kanji Damage (“where you learn kanji with yo mama jokes”) is one the better ones: their way of learning the onyomi (Chinese reading) reading for 休 (kyuu) is this mnemonic sentence: “The CUTE (kyuu; キュウ) person rests against a tree.”
It will also help if you learn if in addition to the reading, you learn a few words associated with the kanji: know not just 休 but also its associated verb, 休む (yasumu: to rest).
As you may expect, motivation is very important. There aren’t any shortcuts; you’ll just have to study a little bit every day, but hopefully these simple tips will aid in the journey to kanji fluency.