Be honest and specific. Explain your goals, what is standing in your way, and exactly what the grant will pay for.
Meet the minimum word count for your level: Primary 1 to 3, at least 50 words; Primary 4 to 6, at least 100 words; JS 1 to 3, at least 250 words; SS 1 to 3, at least 400 words; tertiary, at least 500 words. Then read it aloud before you submit.