What other careers, apart from working for an Airline are available to some one with, lets say a CPL/IR with an Instructors rating??
Typically this can happen...................You start at your local flying club as a full time Instructor. Soon local people with their own a/c cotton on to this and you get asked to fly as their safety pilot around the UK or possibly abroad (all expenses paid.)
Then the local air taxi firm gets involved and asks you to help out. You soon build multi hours quite quickly. Then other doors will open with companies like NetJets, Gamma, Titan, LEA (there are lots more around the UK) and gradually you move up the a/c ladder (if there is one) and add ratings to your license like Kingairs, Citations and Gulfstreams to name but a few.
Then if you feel inclined to do so, you apply to the airlines with your 2000 to 6,000 hours.
Easy!