Another option is to shoot at 2K and then reduce the clip when editing to 1080. It will crop out the prop guard and occasional landing gear edging into the picture.
I feel kind of lucky as I am having very little of this occurrence- but then I fly stable and deliberate when filming, and as previously mentioned I tend to do a lot of angles flying backwards.
I try to fly towards my subject and then bank up and back slowly as I turn to get the few seconds of footage I want. Approach the subject you are shooting from various angles and fly up and then off to the side or back .
I also do not see anyone who takes any real serious footage using the guards... but then again, they don't use Phantoms either *snork*