A good way of enhancing your skills and improving your CV is to do some voluntary work. This could range from helping out in your local charity shop, to doing conservation work overseas during the Summer break.Voluntary positions are normally a lot easier to find and can be a lot more flexible than paid positions, making them ideal when you have a lot of studying to fit in.
Just a couple of hours a week will enable you to help out a community or charitable organisation, whilst providing yourself with some (unpaid) work experience, skills practice and anecdotes that you can use as evidence of your skills.
If you are looking for voluntary work, a good place to start is your Students' Union, as many universities have volunteering societies that work on projects in the local area. Charities are always looking for volunteers in their shops, so you could try these, or take a look at some of the websites above for more ideas.