Japanese Kanji is beauty of combining meaningful parts to create a word.
Here is a tip for the creation of your original kanji.
1. Think of a word or sound that reminds you of the theme (this year's theme: "fun").
2. Collect radicals and components that relate to the theme.
These sites are useful resources:
Resource for advanced learners:
Kanji dictionary. Especially Shimomura's Kanji dictionary for elementary school students (publisher: Kansei sha) has rich information of radicals.
3. Combine the radicals and mnemonics in a creative manner, and have multiple combinations.
4. Select your best Kanji, then write it on a paper and take a picture to upload! (see How to apply page)