Here is a confession: I buy my colognes from the local dollar store (yes, they are $1 each). These are imitations, or rather "versions" of better known and undoubtedly more expensive brands. Despite their price, they smell pretty good.
When I am getting ready to go on a long trip, I break open the metal seal around the neck of a perfume bottle, remove the cap and transfer some of its contents into a smaller plastic spray bottle, which is lighter and takes less space.
In the process, any remaining cologne in the bottle from a previous trip gets mixed with the new one. I don't bother to label the bottles. So I often end up with totally new bouquets. They too smell pretty good.