OASC like to see people who have been rounded a bit, through working with different ages/backgrounds/abilities etc. Have a think about where you could volunteer/help out with something that will assist on this, and perhaps also develop leadership/team skills at the same time. Duke of Edinburgh is a classic route, but you can no doubt think of others.
If you are going to travel, do so with a purpose. Eg. go to South America where you could learn Spanish, volunteer in schools/community projects, travel etc all together. Just travelling and working from bar to bar doesn't say so much.
As far as aviation is concerned, take up gliding. Great for basic flying/poling skills, cheaper, and usually in a club environment.