Yep, just practice, the more time you spend knitting, the more even your tension becomes. Look at knitting videos on Youtube for ideas on how to hold the yarn in your hand/fingers and see if a different method will help. You can take some yarn and just do samplers of different sts with it, rather than practice on a project. If you keep at it long enough, the sampler might make a scarf or doll blanket.
sue- knitting heretic