If you're not a perfectionist, then you can do it yourself with cans. The trick is to take your time and make sure the fenders are prepped and wiped clean with lint free rags. Any oil or contaminants, including fingerprint oil, can cause fish eyes in the paint. Generally, I do 3 - 4 lighter coats of base color, letting it flash/dry for 30 minutes, followed by 3 - 4 heavier coats of clear. For both, try to do 50% overlap coats.
A few words of caution, start with good primered and clean fenders and:
1. Don't freak out when you see the color without the clear. It typically looks weird/off, until the clear is applied.
2. Don't freak out if the clear looks cloudy. Humidity can sometimes cause this, but it usually goes away.
3. Make sure to let the color dry 30 minutes prior to the application of clear.
4. Make sure to let the clear dry at least 24 hours before wet sanding (If bugs or debris get in the clear, they can be removed by wet sanding.
5. If you do wet sand, use 1500+ grit paper and use a block (Using just your hands can cause uneven sanding).
6. Make sure you have a stable and clean place to work (I've had things fall on the ground after painting them and trust me here, it's a sick feeling!). I have several stands like this one that work great for smaller items like a fender.
https://www.harborfreight.com/200-lb-capacity-portable-work-stand-38778.html
Lastly, when reassembling everything, keep in mind that the paint and clear can still be a little soft for a couple days. I know it sounds like a lot, but it's really and easy process and you can get good results on smaller things like fenders. If however you want perfection, it's best to take it to a professional.
