Some gardening, maybe learning a language, a bit of travelling, spending time with the grandchildren.
Or perhaps entering an international beauty contest with the ultimate aim of launching your modelling career on the world stage.
For Choi Soon-hwa, it was a no-brainer.
This week, the 81-year-old took to the stage with women a quarter of her age for Miss Universe South Korea, hoping to make it to the finals in Mexico later this year.
The question, though, is why?
"After raising children and going through hardships, it’s just two people left, and that’s when you need to find what you want to do," the former hospital worker explained to the OceanNewsUK shortly after she came off stage.
"Once you find it, it becomes the energy that drives your life, leading to a positive outlook and healthier relationships with people, which in turn helps your well-being."
For Ms Choi, the thing she wanted to do has been modelling, ever since a patient suggested she take it up at the spritely age of 72.
The comment gave her the confidence to take the leap after several years of financial hardship, which had pushed her and her family to the brink of ruin.
In the years since, she has become a familiar face in South Korea - including walking the runway at fashion week - but launching a career outside the country has proved difficult.
So when Miss Universe, the famed beauty pageant which began nine years after Ms Choi was born, decided to throw out rules banning entrants over the age of 28 earlier this year, she jumped at the chance to take part - making her the oldest ever contestant so far to take part.
"It was something I couldn’t have imagined," she says. "For several years, I had wished to step onto the international stage as a model.
"However, there was no clear path or guidance for me, but since the Universe competition had no age restriction, I participated with the goal of reaching the global stage."
The removal of age restrictrions come as the Miss Universe competition has moved towards becoming more diverse in recent years - allowing married women, transgender women and single mothers to take part.
But her entry still caused quite the stir - not least among her competition.
"The participants were surprised to see me, and when they learned I was 80, they expressed admiration, saying, I want to age like you," she admits.
And it has brought her the international interest she was hoping: Ms Choi has garnered headlines around the world.
What it did not buy was a ticket to Mexico: the Miss Universe South Korea crown went instead to Han Ariel, 22.
Ms Choi didn't walk away completely empty handed however - but with the title of "Best Dressed".
"Just being able to participate is an amazing and honourable experience", she says, adding that she hopes she is the first of many older women to compete for the crown and, by extension, challenge beauty norms.
"Since this is still new, there’s a lot of buzz, but as more seniors participate, perspectives on them will shift, and there will come a time when seniors can compete in world competitions," she says. "But for now, it’s still time for the young to take the stage."
And whatever happens next, she knows some of her biggest fans will always be at home in the form of her grandsons, aged 23 and 24.
"My grandchildren cheer me on, saying, 'Our grandma is so cool, pretty, beautiful, and the best!'"
