I did this on Monaco - Port Hercule, following the order. If you collide with anything, no matter how minor, use a flashback. You don't need to get perfects in each of the tricks but try for as many points as possible. Note that after the start I went to the right; the same can be done on the left side which is effectively a mirror-image of the side I focused on.
1. Air Jump off the start, then straight into second air jump
2. Drift straight ahead and to the right (first drift chute)
3. Spin in the zone right out of the drift
4. Drift back through same chute going other way
5. Drift through zone on either left or right
6. Smash one of the two rows of blocks
7. Donut (or spin)
8. Smash other set of blocks, repeat on other side
9. Donut (or spin)
10. Return over air jump to first drift chute
11. Drift through, then drift through trailers
12. Spin
13. Drift through trailers second time
14. Spin
15. Drift through chute
16. Donut
17. Drift through trailers once again
18. Spin (if there's enough time)
YouTube link below shows part of the 500,000 run I had (game only lets you upload 30 seconds).