Custom flag and how to

Hi does anyone know how to make a custom flag or any good websites youve bought a flag from?
cheers!

http://www.flagmakers.co.uk/

or take your pick here......

https://www.google.co.uk/#output=search ... 60&bih=588

These have been mentioned in the past: http://www.barmyflags.co.uk/

Can design it online too.