Whether you're starting out or scaling up, time will always be your biggest constraint. There's never enough time to do everything, and growth introduces new responsibilities that further erode our finite capacity.
There are plenty of productivity "hacks" for short-circuiting habitual profligacy, but there's clearly an upper limit on how much additional time we can wring from an average day.
Moreover, Parkinson's Law advocates that work expands to fill the time allotted, so there's a good chance that efficiencies in one domain will simply lead to inefficiencies somewhere else.
Since (significantly) more time is wishful thinking, optimising how we utilise our capacity offers more productivity potential than scavenging a few extra minutes here or there.
To-do lists (and similar tools) are a logical starting point because the benefits of planning our work in advance ought to be self-evident. However, the problem with to-do lists is that they're prone to bloat: it's unlikely that you're going to get everything done, so the incomplete tasks inevitably roll over to the following day and get compounded by the perpetual influx of new assignments.
Before long, everything important is also urgent, and everything urgent feels important.
The antidote is a to-don't list, which is exactly what it sounds like. Write down the stuff that you definitely won't do today. Not only is it incredibly liberating to take back control and cull the stuff that you know you're not going to get around to doing, it also helps to bring the really important stuff into sharp relief.
Much like completing a complex puzzle, it's a lot easier to begin by setting aside most of the pieces before starting with the corners and edges.