Reads on Nassau Street (the old easons one) has Circle sticky labels - 600mm diameter. They are a little small, I used publisher to setup a template and print them 12 at a time, all printers should take the a4 label sheets and they come off handy in soapy water - so you are not going to lose any bottles. Its quick and easy.
However I am thinking of moving to A6 100mg paper with prit-stick or gum. I have a gillotine and the paper is 8euro for 500 sheets (cheap as chips). This will be a lot more effort with cutting paper and sticking them on.
I suppose its all a matter of how much time and effort you are prepared to put in.