I like to use Memrise when I’m learning a language and, generally, it is best to make up your own mnemonics when learning. Here are the steps I use when making mnemonics for learning new scripts:
- What is the romanized letter, or what does it sound like?
- Find a word (preferably a noun) that begins with this sound, letter, or at least contains the sound (like “oo” could be in “book”.)
- Try to figure out a scenario using two words with this sound, that also roughly matches the shape of the character.
- Draw a picture of that scenario.
Here are the mnemonics I’ve drawn for learning Devanagari vowels: