Far East Shortcut 

• After the Blue Boost that's hanging out in the air, you'll hit a bunch of small waterfalls followed by a Tunnel. If you jump on top of the Tunnel, you'll cut you're time in half for that section. 

Venice Canals Shortcut 

• When you get to the part with the three hard turns in a row (left, right, left) you can skip all of this by jumping over the island in between them both. This comes shortly after the part with the docks.