Katakana was developed from parts of Chinese characters as a form of shorthand. So to memorize katakana, it will help you a lot to refer to Chinese characters. For example, リ comes from the right side of 利.
The list below shows the origins of each katakana.
This section contains lots of useful grammar notes which will help you improve your Japanese substantially. If you have further queries on grammar, feel free to ask us and we will try our best to answer them =)