Getting to 50 isn't a problem. A member of this forum (youtube name wipeout2097xl) posted this video /watch?v=lKe6j8ubcDA. Essentially you can just go afk and leave your game on. Probably best to do it overnight. Might take two nights if you're starting from scratch.

I would just direct you to his original post but I don't know where it is. It seems most of the threads in the 2048 have been hidden? o.O Anyone know why? I can still access them by searching on google but I can't get to them directly from this site.