Try to use the mnemonics provided by Renshuu. Try to learn 3-5 terms max, so as not to overwhelm yourself. Try to have patience, try to have more importance to time, time to time you will be able to see that you are improving. Happy learning!
For mnemonics to help remember them, I have personally found that the Tofugu published version was the most comprehensive reference for both hiragana and katakana. But that's a matter of taste. If you use a textbook, it might have something like that. Plenty of other sources too have their own versions.
For the extra practice to study outside of Renshuu, I also used a bunch of outlets, including Tofugu, such as the Learn Japanese to Survive RPG series. They also helped to reinforce my memorization and spelling.
