I would plan out what I wanted to have on the mind map, and account the space. If I knew that I wanted to do a theme and have a section for each of the characters, t hen I would separate the page into the number of characters I needed. I try not to write in full sentences on a mind map, it needs to be short and snappy. I also would colour code mine, for example in science I would do required practicals in red and formulae to learn in green.
For flashcards it really varies per subject, so which subjects do you need help with?