“Some days there won’t be a song in your heart. Sing anyway.” –Emory Austin (Source: Online Wellness Network)
This sounds like good advice to me (as long as they are happy, uplifting songs). I also find that smiling, looking up, listing my blessings, hugging loved ones, doing a kindness for others, forgiveness of others and myself, reading uplifting books, watching comedies or uplifting movies, and being with or communicating with upbeat friends, all help to pull myself out of a funk.
I’ve also found that most negative, disempowering, envious, debilitating, and anger inducing thoughts are ego driven, and once I label them as such I’ve found it is much easier to quickly dismiss them and move on to more positive and uplifting ones rather than dwelling on the negative and re-running a series of old and negative messages my ego tends to conjure up if I let it.