I just did a little experiment and crossing them over seems to be a pretty satisfactory way of doing it. This may be somewhat strange to get used to with the right lever operating the rear from the drops and the left operating the rear from the top but it gives the smoothest cable routing i could come up with. If you get the cross levers close enough to the stem it makes the routing from the bars to the bike pretty similar to a mountain bike. You could also use noodles for tighter curves if you wanted to try something with more drastic bends.