Well the best way is the old technique.
using brings and a rope.
Tigh a rope to little head and a small brick.
walk the whole week with that, all day! incl at work.
next week 2 bricks and so onward.

disregard any comments from co-workers or ex girl f.

Just walk proud and tall and you might meassure 2-3 centimeters more after six months or so.