When you invoke the Muse, you are calling on a force from a different, holier plane to aid you with creating your art. You are not asking for brilliance or success, simply for the inspiration to keep your art going.
Say a prayer to the Muse right before you sit down to work on your art.
Say it out loud and say it in earnest. Then, you can start working on your art.
An example of a prayer to the Muse is the “Invocation of the Muse” from Homer’s Odyssey, the T. E. Lawrence translation:
“O Divine Poesy, goddess, daughter of Zeus, sustain for me this song of the various-minded man who, after he had plundered the innermost citadel of hallowed Troy, was made to stray grievously about the coasts of men, the sport of their customs, good and bad, while his heart, through all the sea-faring, ached with an agony to redeem himself and bring his company safe home. Vain hope — for them. The fools! Their own witlessness cast them aside. To destroy for meat the oxen of the most exalted Sun, wherefore the Sun-god blotted out the day of their return. Make this tale live for us in all its many bearings, O Muse. . . .”