I have found that "King of Shaves" shaving gel is best suited to my beard but is sells in 135ml tubes which exceed the 100ml maximum permitted for carry on baggage. I tried their shaving oil and it simply doesn't come (or shave) close. Which is a pity as a bottle of shaving oil takes up no space at all.
My solution is to decant around 100ml of gel into a re-usable plastic bottle. This bottle has an opening large enough to stick my index finger inside and this is where the cost-saving comes in! A finger or so coated with shaving gel is just right and far less than a typical squeeze of the original packaging. So my shaving gel goes much further than it used to!
Unfortunately the savings don't compensate for the extra airport tax on the airline ticket.