If I have to remember something, perhaps to call someone at a specific time, or in a specific place, I do this:

I visualise myself just arriving at the place or time when I have to remember, then I picture myself remembering. The "just arriving" bit is very important - it seems as though the sense of something happening or changing is enough for my brain to kick in, to help me to say "Aha!"

So, if I have to remember to call my Mother when I get home, I picture myself taking off my boots and remembering to call my Mother. Note I don't picture myself calling my Mother, just the act of remembering.

This works, maybe 90% of the time.

Silly question; is this mnemonics?