I have a friend who worked at Cambridge university as a lab technician after her undergrad. While she didn't get a PhD at that university she did then move onto a PhD at another university, and her experience working as a lab tech was seen as a big plus. I think getting a bit of experience at a uni would be a help - anything you are involved in (field work, lab work, data analyis, teaching, etc.) will be something you will probably come across in the course of a PhD.