An occasional surprise can keep people on their toes. When things get stale and people begin to lose motivation, try changes things up a little. 

A good way to get someone's attention is to surprise them. You create surprise by breaking expectations. 

Example - "Monday"..."Tuesday"..."Wednesday"..."Thursday"..."Saturday"  

You expected Monday-Thursday, right? But "Saturday" was unexpected. It surprised. 

Ways to break expectations -  

1. Change your routine - ex. Do something unexpected 
2. Interrupt their routine - ex. Add something new or change employee routines 
3. Change the schedule