Many people spend their 20s getting some unhealthy behaviours out of their system — like sleeping until 2pm on Saturdays and spending all their disposable cash on new kicks. But your 30s are an ideal time to cement the habits that will help you achieve personal and professional fulfilment for the rest of your life. To give you a head start, we sifted through recent Quora threads on this critical life transition and highlighted the most compelling responses. Here are 10 lifestyle tweaks you can make in your 30s to lay the foundation for lifelong success: 1. Stop smoking. If you've started smoking, stop immediately, suggests Quora user Cyndi Perlman Fink. While you can't undo the damage you may have already incurred from smoking, research suggests that those who quit before age 40 have a 90% lower mortality risk than those who continue. 2. Start going to sleep and waking up at the same time every day. It might be tempting to use the weekends to recoup your sleep debt, but Nan Waldman recommends you hit the hay and wake up around the same time every single day. If you oversleep for even a few days, experts say you risk resetting your body clock to a different cycle, so you'll start getting tired later in the day. Avoid a lifetime of sleep issues by sticking to bedtime and wakeup routines whenever you can. 3. Start exercising regularly.