I'm not in the game development field or anything, but I can say that the best way to get work in a specialized field is to have knowledge in it, even if you train yourself. What you practice with all depends where you want to work into a development process, too. Best thing like one of these other guys said, is to get familiar with game engines like unreal or cryengine. Just try out different projects, work on specific aspects. I'm sure hiring developers like seeing self-made games, but you're not applying to make the whole game. Perfect yourself at something and make that your outstanding talent. That goes for a lot of things, not just video game design. People like to see that you're good in all traits, but they most certainly would prefer an expert in a certain field in designing over the jack of all trades master of none.