Get aviation work experience while you train
If you're still at school and have never worked in aviation before, or perhaps you're an aviation undergraduate or have a great job in the industry but trying to get to the next level up…
First off, have a look at the opportunities around you. The opportunities available to a 25yr old with a car and an income differ greatly from those available to a school student on public transport. But a good starting point is to have a look at your local airport or airfield on google maps and make a list of every aviation related firm around the perimeter. Differentiate between charities and businesses. Have a look at the websites for work or volunteer positions currently open. Then after you've done your research visit them. A museum, charity or flying club is a good place to get a tea if there are facilities, mingle and chat to a few different people about their experiences there.
A business is a good place to go smart, clean and fresh, neat and tidy hair and with your logbook, folder of achievements and a CV. Greet everyone with a good handshake (ladies, you too should master the art of a firm and polite handshake), treat everyone like they might give you a job and be interested in the work going on. If you go on a Friday be prepared to try a trial shift on a Saturday or to have a spontaneous mini interview about what you could bring to the business, your goals and plans for the future. Be honest about your pilot ambition, you might meet like minded people that support and motivate you along the way.
If you already have a great job working (for example) in ops for an air operator, you might look for an opportunity that gets you mingling with other pilots more regularly or in a flying club where as staff your flight training could be heavily discounted (a great benefit to have!). It also puts you in a position to be able to more easily approach instructors for guidance and support and to meet like minded individuals with great tips and advice, who will likely hold you accountable, and might even support you and join you on your journey - never a bad thing to have!