ND Filters are a must have for any DJI drone allowing you to set proper shutter speed for just the right amount of motion blur between frames. Some filters will help you get better color, contrast, and saturation. PolarPro has made a set of ND Filters available for the DJI Mavic Pro starting at $49.99 for a 3 pc Kit, and $99 for a 6 pc Kit (found here).
There's no denying PolarPro makes awesome filters, and it's all about the quality of glass when you're trying to get the best image. But if the price of $49 and $99 is too steep for a Mavic Pro Drone, there are now filters showing up on eBay starting at $6 dollars for a 6 pc kit. I personally am willing to take a stab at the $6 dollar versions first and once they come in, i'll share some of those results. You can find a variety of Mavic Pro Filters popping up on eBay in the last few days (found here).