Best way to get autographs is to have GF send you two signed tourbooks by all bandmembers to your home address for free. You only have to wait for the postman. Still have one of the tour books somewhere in my bedroom, should look at it more often, really.
Option two: Be at the right place at the right moment. Had to wait three hours before the Amsterdam KTGC showcase to get an autograph but it was worth the wait, was the first to meet MK and have my KTGC cover signed. Honestly, I don't think there is a recipe to get an autograph. It depends on so many things (size of the arena, weather, schedules, traffic) so basically there's not much you can do. I suggest when you succeed, you immediately buy a lottery ticket too as it's your lucky day.
Anyway, it's a nice addition to a collection of albums. Meeting him is nice, but I personally don't see the 'kick' of having each album signed. I like his music, a nice conversation about music would be awesome (although I assume he has better things to do than talking to me). Having one (or in my case two) autographs and the memory of meeting him is enough. At this moment I wouldn't sit down in front of a venue to wait and get another autograph.