Repetition! I believe the first ones are the hardest. Once you know the first ones you start to see patterns. Once you learn moon you see it in morning and you make associations. You realise that one moon cycle is a month. I'm horrible with remembering kanji so I had to use skritter when I started learning: http://www.skritter.com/ I think memrise is a good alternative but it's not the same as when you draw the characters. I also made sure to start with the easier kanji and make my way up to the harder kanji. A text book always starts with the easier kanji first and then build on that. I recommend following this process.

I agree with what the previous answerers said and definitely try what they said. When I practice kanji, I usually say the readings and the meaning(s) out loud while writing them. As you get into harder kanji, it also helps to study the parts of the kanji while you are learning them. Knowing many of the parts' meanings will help you figure out more new characters later on. For instance, you've may have seen 泳ぐ (およぐ to swim), the first three slash marks on the left are is the radical that always means something to do with water. It's not something you necessarily need to worry about at the beginning, but as you get further into it, it would probably make your Japanese study a bit easier. Also, if you can create mnemonic devices for some of them - that really helps! Obviously, it's incredibly difficult to do for every one that you encounter, but it is also very helpful. Whether you create them based off of appearance or something else! For instance, "I never recognize 認める (みとめる, to recognize)." Or 人 ( ひと, person）looks like a person. Anyway, がんばってくださいね！

Start with the fundamental, absolute basic Kanjis. That's where the secret lies. Before you begin learning advanced and complex kanjis, having a foundation of the basic kanjis will speed up your memorisation level as well as improve your effective recall.