You pick up your flashcards and study a few you know - so far so good. You hit a card that you've studied a dozen times before, and doubt kicks in. You stare at the card for a minute, wondering if you are studying the right way. You set it aside, knowing that you need to write it out later.  You study a few more cards, then hit one you remember well, but aren't sure about the meaning. You search for the word on-line, but the meaning still isn't clear. Back to the flashcards, you find one that is similar to another word, but you aren't sure whether you remembered that other word incorrectly. A while later you find a flashcard that has a typo on it. You drill five cards in a row that are super easy, and wonder if you are wasting your time. You spend time making flashcards from your lesson, but run out of time to review them.  The result of an hour of studying is this: you are exhausted and filled with doubt. 

Your brain runs on automatic most of the time.  When you activate that analytical "how can I be doing this better?' part of the brain, it uses energy. When you activate that "this if frustrating, but I need to push myself to continue" part of the brain, that is exhausting too. Your brain runs on automatic even when you sleep. 

Wouldn't it be great if you could learn kanji on automatic, without having to tweak your system or being overly frustrated.

My biggest problem with learning to study kanji was the expectation of how long it takes to learn a word. I thought I could learn a word over a few days, with a few sessions. WRONG! Here are the steps I go through now:

1. Recognize it is a new word.
2. Recognize the pronunication
3. Understand the meaning in a general way
4. Recognize the kanji that make up the word.
5. Identify what word it is similar to (how you remember it)

You need a hook, or a way to remember the word, which is step 5. Brute force memorization works (after 100 times) but it is way easier to find a way to remember it. Here are some tricks:

1. Hear the word on TV and recognize it.
2. See the word on a sign, book or article and think, I need to remember that.
3. Use the word in a sentence with a teacher or native speaker, and observe the correction.
4. Write the word repetitively (if ten times isn't enough, write it eleven times, etc.)
5. Find a similar word (or opposite) and remember the set.
6. Create a group, and study the group.  

That last idea, studying a group, is the one that is the most repeatable for me. The benefit is that you can remember the cards in a group.

So how do you study kanji without exhausting yourself?

1. Reviewing cards is easy. Do that first to warm up.
2. Study new cards you were trying to learn yesterday.
3. Skip the hard ones if you start to get frustrated.
4. Delete the impossible cards without regret.
5. Time box each card (limit the time you spend on each card)

The idea is to keep studying cards without seriously questioning your study method.