I think about the infinite possibilities of expression there are, in particular in music, photography, films and writing. the ability to reflect on life, whether in good times or bad, makes me feel good.
"The world sucks and you're the only one who can change it!"
...I play a lot of video games.
On less dramatic days I just like to remind myself of some old quote before I start the day. I keep a very long list of inspiring quotes on my laptop to look at when I'm feeling defeated. My most recent "mantra" is this nugget:
“Your time is limited, so don’t waste it living someone else’s life. Don’t be trapped by dogma — which is living with the results of other people’s thinking. Don’t let the noise of others’ opinions drown out your own inner voice. Most importantly, have the courage to follow your heart and intuition. They somehow already know what you truly want to become.” (It's a Steve Jobs quote, so I'm being totally hip right now.)
I suppose my mantra is 'everything works out in the end'. Since it doesn't matter how much you worry about anything. It has little effect on the outcome. And, you can put a positive or negative spin on any outcome. So, I search for the positive angle and work to believe in it.
To be optimistic--the fact that if good times do not last forever, even the bad times would pass away. Start each day with new hopes, new energy and new enthusiasm. This is life-- pleasure and pain, joy and sorrow all go side by side.
What keeps me going mostly is the fact that each and every day is different and I am different each and every day. I try to make a plan for each day of what I want to accomplish - depressed or not. Life isn't all that wonderful as it was at this time in place for me - so I really must push myself to keep going. Keep on - keeping on.
I don't normally need motivation to start my day. However, when I hit the rough spots that we all do in life, I do have a mantra. It's "put one foot in front of the other". That reminds me to do everything I can to get out of the bad spot. File papers, look for jobs, call a repairman, make necessary doctor appointments, etc. Whatever it takes.
I've found that if I do all of the things I need to do, no matter how pessimistic I may feel or how unimportant the action seems in the circumstances, I'm creating doorways out of bad times. It has always worked for me.