Settle to
Definition 1 of 2
Pro Tip 1/3Motivated Restart
Use 'settle to' when someone begins a task with focus after stopping or being distracted. 
The students chatted briefly before they settled to their exam preparations.
Pro Tip 2/3Post-Interruption
'Settle to' implies that there was an interruption or break before starting the task again. 
The team settled to their project after the unexpected fire drill.
Pro Tip 3/3Mental Preparation
Suggests a person is mentally preparing to concentrate on a task or activity. 
She took a deep breath and settled to writing her thesis.