Question: what bra size is best?
Answer: The rule of thumb is as follows: If you go up in the band, go down in the cup and vice versa. For example, a 32C could possibly fit a 30D or a 34B. If you're a 34C, you might find bras that fit better in a 36B or a 32D. Knowing your sister size is useful to accommodate for size differences between brands.