Most of your crashes are predicted on how you are hitting with the wind. Go with the wind to go insane (pressing up), or press down to slow down and be able to land and keep on driving.

Drive on the wrong side of the road and press r1 and your boost meter will not go down.

There are many different takedowns proformable in this game.
Revenge Takedowns: If you have a revenge rival, the marker above their car will turn red after they take you out. Take them out to get this takedown.
Traffic Check Takedowns: You do this takedown by hitting random cars into the path of your rivals. They will almost always crash if you personally hit the car in their way.
Regular Takedowns: Any time you cause a rival car to crash with your own car being the battering ram.
Psyche-Outs: I currently have no idea how you do one of these. Sorry.
Verticle Takedowns: These are, by far, my favorite to do. Using a jump, ramp, or, if you get lucky, you can even use the back of their car to get on top of them.
Explosive Payback: After you crash, you use a crashbreaker to take out any other rivals.
Aftertouch Takedowns: Steer your wrecked car into the path of your rivals to cause them to crash.
Instant Revenge: If you are taken out by another rival, and you immediately activate your crashbreaker and catch them in the blast, it is considered instant revenge.

Double takedowns: Any time that a rival you caused to crash cause another to crash, or you hit two rivals and cause them both to crash at around the same time, it will be a double takedown. Regular takedowns, psyche-outs, aftertouch takedowns, and verticle takedowns will become this if causes another car to crash.
Triple takedowns: The same as double, only with 3 rival crashes.
4-Way takedowns: The same as double, only with 4 rival crashes.
I am not sure if there is anything possible after 4-way takedowns, but that is because I have never experienced it.

Double Payback: When you use your crashbreaker and cause two rivals to wreck. If an exlposion of a rival catches another rival in the blast, double payback will also occur. Only explosive payback will become this.
Triple Payback: The same as double payback, only 3 rivals wreck.
4-Way Payback: The same as double payback, only 4 rivals wreck.
Total Payback is the ultimate destroying move in this game. After you wreck, if you use a crashbreaker and wipe out all 5 other rivals in the blast, or chain of blasts, you will obtain this. It adds a huge boost to your rating level, and your boost bar becomes x4 and completely fills. I've done this once, and it was the coolest thing ever.

Hope this helps. :)

There are many ways to earn boost, and some are more effective than others.
The 1st is tailgating. I don't much agree with this method, because, why stay behind your rival when you can either pass them up or shove them into a bus? Anyways, just stay very close and almost directly behind a rival to get tailgating boosts.
2nd, is checking traffic. Not the fastest way to get boost, mainly because you slow down dramatically when you hit somebody, and it doesn't provide that much boost. Just run into drivers to get this.
The 3rd is the complete opposite of checking traffic, near misses. You get close to the side or back of a driver, and at the last minute, if you're behind them, swerv out from behind them. Get about a foot away from either side but don't hit them to get it another way. One great combination with this is going into oncoming lanes and doing this. This way, you get oncoming boost and near miss boost. Also, if you alternate, you can nearly miss a couple and them ram into someone. If you alternate quick enough, you can get near miss and traffic check boost.
The fourth is air. Going off a jump is always an easy way to get boost, though not very much. The amount of boost and stars you get for air depends on two things, your cars weight and the track you are on. The heavier you are, the faster it will go up, and the less jumps on the track, the faster it will go up.
The 5th is takedowns. All takedowns will give you a chunk of boost bar, except for aftertouch takedowns, because you were already going to lose a chunk when you were done with impact time. All takedowns, except on rare occasions, if you have a x4 boost bar and no boost, the traffic check takedowns, will completely fill your boost bar. The last are different moves you do to your opponents, such as rubbin', tradin' paint, shunting, and slaming.

All of these ways also increase your rating, but takedowns increase it the most. The more frequently you do one of these, the more it contributes to your rating.

In any Burning Lap or Preview event, stay in oncoming lanes. There are few cars period in this mode, so dodging will not be a problem. You will gain more than you use, so hold R1 with all your might.
In GP's, focus on winning 1st place, not your rating. Your rating stays, so you can get Awesome in 3 to 4 races and focus on winning.
In Road rage events, don't use speed, use cunning. If you pass up a few rivals, slow down and let them pass again so you can have a second go at them. If it is a Crashbreaker road rage event, be careful with your CB. Using it will make you get to "Damage Critical" faster.
In Traffic attack events, don't use turbo until you can't see cars in front of you. The slower you go, the more cars you can hit. Also, hit the cars in the back right side, or back left in Central Route, so that they are hit into the oncoming lanes.

Hope this helps. :)

Take out your revenge rivals as much as you can try and get signature takedowns at the same time.

BURNOUT: REVENGE

Black Elite Racer
Reach the "Elite" rank to unlock the Black Elite Racer.

Criterion GT Racer
Successfully complete the White Mountian Challenge Sheet to unlock the Criterion GT Racer.

Custom Classic
Successfully complete the Sunshine Keys Challenge Sheet to unlock the Custom Classic.

Dominator Assassin
Have a saved game file from Burnout 3: Takedown on your memory card to unlock the Dominator Assassin.

EA GT
Successfully complete the Central Route Challenge Sheet to unlock the EA GT.

Etnies Racer
Successfully complete the Motor City Challenge Sheet to unlock the Etnies Racer.

Euro Classic LM
Successfully complete the Eternal City Challenge Sheet to unlock the Euro Classic LM.

Hot Rod
Successfully complete the Lone Peak Challenge Sheet to unlock the Hot Rod.

Logitech World Racer
Successfully complete the Rank 10 Ultimate Revenge GP to unlock the Logitech World Racer.

Madden van
Have a saved game file from Madden NFL 06 on your memory card to unlock the Madden van.

Nixon Special
Successfully complete the Eastren Bay Challenge Sheet to unlock the Nixon Special.

Revenge Racer
Get a 100% game completion to unlock the Revenge Racer.

Easy Crashbreaker
When your Crashbreaker meter is at 99%, press X. You will only have to tap Circle two or three times to get a full Crashbreaker. Additionally, hold R1 until the Crashbreaker meter gets to 100%. When it does, it will be easier to blow up your car with R2.