Jim, I was out hacking around a golf course. 
After my worst start in months: three straight doubles on a course I “know,â€ I fought back for a score in line with my handicap. Only one penalty after I blew a drive wide right (a sure sign of fatigue; did go to the gym last night and pumped too many weights), but NO THREE PUTTS. The mental game saved me.

So to your questions:

1) What do you think of this new title, "The Young Champion: How to Toughen Up Your Mental Game." 
1. Be a Young Champion: Win Mentally
2. The Young Champion: Let Your Mind Be Your Coach
3. Young Champions: Mind Over All that Doesn’t Matter
4. Be a Champion Now: Your Body Is Strong and Your Mind Is Strong
5. The Young Champion: You at Your Best Now

2) Any refocus words or phrases you'd add to this list: 
Snap back
Be all here
One shot at a time
 We’ll take the next one
Let’s get this next one
Back in control
Next play is ours
We got this
Refocus Reboot
Take a moment 
R & R (regroup and re-engage)

Would add:
Slow the situation down
Breathe deeply
Think only about the task at hand
No If’s, just results
Improbable is not impossible