The phrase "a personal effort" is correct and usable in written English.
It can be used to describe an individual's own initiative or work put into a task or goal.
Example: "Achieving this milestone required a personal effort from each team member to ensure success."
Alternatives: "individual contribution" or "personal contribution".
Mr. Obama needs to make much more of a personal effort to keep this important pledge.
Almost everybody would like to see carbon emissions drop, but closer to home, not many make a personal effort.
Many of these people had made a personal effort to save this creature, and now they reveled in its silent and stately stillness.
Ferguson made a personal effort to ensure Pereira chose United, a common tactic for the club's manager when looking to coax young players to join.
"That means as well as supporting our professional body, the BMA, we will extend a personal effort to ensure our patients' care.
US president Barack Obama has made a personal effort to promote Burma's transition to democracy, travelling there twice in the past three years.
A little personal effort and a sincere gesture of appreciation are all that's required.
Resilience may not come automatically – dealing with a life-threatening disease and intensive treatment requires a huge personal effort.
The musicians claimed to be the primary songwriters on two tracks, and major contributors on several others, though Gordon Williams, a prominent recorder, engineer, and mixer on Miseducation, described the album as a "powerfully personal effort by Hill" and said "It was definitely her vision".
After years of eschewing direct involvement in Middle East peace talks, he has embarked on an intensive personal effort to reach a deal by the end of his presidency.
"This is a highly personal effort, more so than any speech John has given," said one longtime friend.
