Sleeping less is certainly an easy way to gain more time on our days, but this needs to be done carefully because if we don't properly recharge our energies, we will have more time but we could also become less productive caused by lack of rest. But I think any person can "survive" with 6 hours sleep easily, and 5 hours from time to time.
Another way of gaining time is of course, do things a little bit faster, if we earn 5 minutes doing the laundry faster, and 5 minutes getting ready faster when we go out, we have 10 more minutes there, and the same can be applied to almost anything.
Cheers bud!