Whenever possible, keep your vehicle undercover and away from constant sunlight. Wash it once a month or more often. If it is dirty wash the dirt off as soon as possible. Bird and bat droppings, leaves and sand can eat into the paintwork, so get rid of them quickly. Consider applying paint protection to your vehicle.
If you’re driving a spankingly new high-value car and crunch a front quarter panel and bend the bonnet, a repair will be most likely. If, however, you smack a low-value car into a guard rail, lose the front bumper, a quarter panel, and bend the bonnet, then the insurance company is likely to write it off. It will be up to the insurance company's discretion.
As with all things DIY, the end result may not be perfect and a trip to your local repairer would ensure the job is done right. Smallish dents can be removed by either pushing out (if you can get in behind the dent), suctioned out (using some sort of plunger or another suction device) or through the application of heat.
Things to look for;
- Different panels not matching in colour
- Drips and runs in the finished job
- Paint on components on which there should be none. (Exhaust, trimming, light covers)