NOT an example of art - but I like the text of William James (yep, interesting brother of Henry) which I found on a page from my sketch diary on 4.9.2020:
"To get into a good mood, one has to straighten oneself blithefully, and act in a way as if the good mood is already there."
For me it works.
What do you do to lift your mood if necessary?
(PS: Question: I wrote "as if the good mood were almost there", but autocorrection stubbornly underlines that with red. Would my word be wrong? Should it, good mood being singular, be "was"?)