If you have a car with good acceleration and nitro, try getting out ahead at the start. Burn your nitro, hit the ramps when you need to refill it. If you don't get boost-killed and the other players bang on each other, you can sometimes win with the lower-ranked car. A maxed-out DS is ideal for this, but with really good nitro like the DS has hit the ramps more often and boost just before the ramp.
If you're using a car with a higher top speed and a lower nitro-rating, don't bother at all with ramps unless it cuts a corner or winding path, but catch the nitro bottles that are always on the ground past the ramps. Most of your opponents will try to hit every ramp and spin 360's, hoping for a chance to boost-kill with a shockwave but it costs them seconds unless they hit each one perfectly. Playing the odds, you'll lose some but every few races you'll get a 1st instead of 2nd or 3rd.
