mo·ti·va·tion /ˌmōdəˈvāSH(ə)n/
noun
the reason or reasons one has for acting or behaving in a particular way. 

A pep-talk is a motivational technique. You're motivating the person to do something specific. 

You've got to give someone a reason to act. So where's that reason come from? 

The first key to a great pep-talk is empathy. Remember - people become demotivated because they're experiencing negative emotions. 

Don't try to change their negative emotion. Encourage them to act on the negative emotion. 

The best and most basic reason to do something is so you can feel better. 

"Because" is a powerful trigger. "I want you to (fill in the blank), because (fill in the blank). 

People are motivated by the chance to feel better. Examples -

• "I know you're frustrated and tired. I get it!" (empathy)
• "But I need you to get this done today...." (direction)
• "...because I don't want it hanging over your head anymore." (motivation)
• "I know it's a pain in the butt." (empathy)
• "So I'd start by doing _____________...(direction)
• "...because that's second nature to you." (motivation) 
• "I know this isn't easy." (empathy)
• "So call me if you get stuck." (direction)
• "...because I'm willing to help.)