Girth is the dimension bodies adapt to slowly, so it’s the one to change deliberately — a quarter to half an inch of circumference at a time. Length barely needs training at all, and you never need to take all of a toy for it to be worth having. Change one number at a time, and let it be girth.

A firm toy reads noticeably bigger than a soft one at identical measurements, because none of the girth squashes away. Going up a step in girth and firmness at once is really two steps. A kind trick: take the new size in a softer pour first, then revisit firmness later if you miss it.

Warm up properly, use more lube than seems dignified, and treat discomfort as information rather than a challenge — if it hurts, that’s the day’s answer, not a negotiation. Plateaus are normal and staying at a size you love is a perfectly good ending. Slow is not a failure mode; it’s the method.