Q:

How to carry cologne bottles in hand luggage and prevent losses?

Say I have a cologne bottle of 100 ml that I want to carry in my hand luggage on a plane trip.
100 ml is the limit so it should be fine for the transport regulations (if not, please let me know!).
The problem I always encounter is regarding the storage of the bottle: how to prevent it from leaking?
What I normally do is to put it in a plastic bag, so that the possible loss remains there. It is fine, only that the bottle ends up quite wet.
What would be a better approach?

A:

This trick is used by many 
Piece of Plastic on bottle before you close the cap 
That will prevent spills. After that put it in ziploc type plastic bag 
Check at home before you put it in luggage.

