Thanks for the tips. I've been working on getting the bed levelling exactly right, which seems to be helping a lot. It's still not perfect, but I haven't had time to sit down and get it exact. I've gotten half the first layer down well, but the other needs work. I will look at a glass build plate in the future as it seems a popular choice here, but without access to one I went with the old standby of blue painters tape and switching off the heated bed.