Okay so I took a gap year this year after completing my under graduation last year. I had applied to only one school last year for post grad and was rejected. It was world shattering. I went into idk pseudo depression for a while but then I geared up and well decided to fully utilise the year.
During my gap year I started interning at two places, with that I read on articles and started working on my personal statement, CV, anything which could make my application better. Now I have 7 acceptances in hand and plus 2 more pending. I reapplied to the school where I was rejected last year. Though I am wait listed there but still!
So gap year can be used for anything to everything! Read books, volunteer, intern, make your apps much better, take a job or just chill for a lil while.
In any case, good luck