*(I write this in response to some dojo'ers that had mentioned to me that they sometimes can't shake doubt. My answer has always been that doubt is 'the lightest form of fear' so don't attempt to shake it, understand it and it vanishes. ) 'from the book,   'Standup Comedy with a side of Chili'.  

It takes....

                                                                                                                                                                               decision

determination

boldness

conclusion

courage

design

earnestness

firmness

fixation

intention

objective

project

purpose

purposefulness

purposelessness

resoluteness

responsiveness

steadfastness

undertaking

will

willpower

One word sums it up actually. Every standup artist must have RESOLVE. Strong overwhelming resolve to do what it takes to allow yourself the expression you need, and that is to make people think and laugh. It's what we got, it's what we are. Your resolve as a standup must be stronger than the tough audiences you will face, hardships of travel, detached bookers unknowing uncaring club owners, road food, terrible hotels, and that constant cold draft of unfairness,  etc etc

Turn to your resolve in those moments and look at list of strong words, use them as a battle plan. Make certain you are putting into play all of these things.

But as you look over the list know that is what you are made of,... it's what you got, it's what you are. Just carry out the battle plan! Don't just possess resolve, use it! THAT'S what it takes to make it.