Celebrate yourself the moment you decide to do something that challenges you.
Don't let the outcome of your actions be what dictates how you treat yourself. Appreciate yourself and celebrate yourself for choosing to have the courage to do something that might not work, because it truly does take courage. If it were easy it would have already been done by somebody or wouldn't need to be done.
Celebrate yourself before you know the outcome, before you even start. So you will continue to value having the courage to do things that that might not work and that need to be done.