Koepka was voted PGA Tour player of the year after returning from four months out with a wrist injury to win two major titles in 2018, the 28-year-old becoming the first player in 29 years to win back-to-back US Open titles at Shinnecock Hills in June.
The world number three then held off a rejuvenated Tiger Woods to win the US PGA in August, joining Woods, Gene Sarazen, Ben Hogan and Jack Nicklaus as the only players to win the US Open and US PGA in the same season.
And although he is technically starting his 2019 season in 2018 at this week's CJ Cup in Korea, Koepka will wait until the new year before assessing how he can get even better.
"I set the goals on a calendar year so I think I'll go out January 1, go to the beach and write down a few goals," Koepka told a pre-tournament press conference.
"Obviously number one is stay healthy because that hasn't been the goal that's gone very well for me my whole career. So stay healthy is probably numero uno. From there I'll reset them come the end of the calendar year."
Koepka was ranked in the top 10 for driving distance, strokes gained off the tee, birdie average and scoring average, but a lowly 113th in strokes gained putting.
"Statistically I didn't putt very well," he added. "I putted well in the majors when I played well, but overall it wasn't my best putting season. Statistically, driving was great. I love the way I drove the ball.
"Ball-striking was really good, so just keep improving on that, try to eliminate those big numbers and just improve on the putting a little bit, which for three years now I've been inside the top 10. This past year I think I was maybe 100th or something. If I do that, I can be there week in and week out."
Koepka's Ryder Cup team-mate Justin Thomas is the defending champion in the £7.2million event on Jeju Island, with four members of Europe's victorious side at Le Golf National - Alex Noren, Paul Casey, Tyrrell Hatton and Ian Poulter - also part of the 78-man field.
