I feed twice a week until they are halfway to breeding size, then switch to once a week. When feeding the twice a week, the meals are smaller, but not by much, as they are more frequent, then when they switch to once a week it's mostly smalls and mediums.
I gotta argue with Capray as it does make a difference weight-wise, especially when bringing snakes up to breed. You do not want to overfeed as it can be unhealthy and even affect the breeding you are bringing them up for (obviously you don't want to underfeed either), but all in all the schedule he is suggesting will take twice as long to get a female ball to SAFE breeding size.