Being a Jedi Knight helps as well.
Joking a side see above. I entered cadetship with PPL+100hrs. Though not all sponsorships need any flying experience I think it helps confince your future employer that a) You can fly and b) Show a genuine interest in being a commercial pilot.
Competition for such sponsorships is stiff. Guys on my selection syndicate were Oxbridge calibre so anything extra such as any flying or aviation involvement helps.
If you do get to the aptitude tests practice mental arithmatic, verbal reasoning etc beforehand. Also, I know this sounds obvious but you cannot know too much about the company, industry and the aircraft they fly.
Oh and one last thing if they ask you who designed the Spitfire don't say Colin Spitfire. It won't go down too well.
Best of luck