When flying a symetrical drone, it is really easy to lose your orientation relative to the drone. There are ways to fix this like turning on an intelligent flight mode or hitting return to home to get your drone back safely and you should practice using the return to home feature at least once in a controlled way so you know how it works. But lets say you want to keep your drone "on target" and filming, then the only thing to do is to regain your orientation. Practicing this with your photo rig is certainly one way to do it, but you might also consider using a $20 CX-10D and the following practice exercise. It can be done inside or outside.
Tips: Small movements work best. If you fly it forward and you could not learn anything about its orientation, try and fly it the opposite direction just so you aren't losing any ground.
I used to have an affiliate link to banggood to buy this but I have had an issue twice already and I just can't recommend them anymore. You should be able to get them off Amazon and Ebay with no problem, just make sure you get the CX-10D.