Sometimes it has really helped me to plan a reward for after I do the challenging action. I especially tend to not be fond of making cold phone calls, so if I've figured out a reward I get once I do so, then I find I am able to plunge in a little easier.

My rewards have been along the lines of - "...once I make this phone call I get to walk up the street and treat myself to a nice mocha and piece of pumpkin bread at the coffee shop..." - something along those lines.