One of the worst flaws in judgment I've identified in myself --
A lot of times, after a big completion push on a project, things seem under control. Maybe I've been working nonstop 12-13 hours, and there's only an hour or two left of work to do, but I'm fading.
So, I call it a day and go to sleep, or whatever. Maybe that's the right call, and maybe it's not...
...but I've seen far too often, the project doesn't get finished in the next 2 to 8 weeks.
It really should get done right away, or at the start of the next day at the latest.
Reschedule meetings if you have to.
But get it done.
If you're 90%+ on something, you really need to go into Terminator Mode on it and get it done. All of the most effective people I know do that.
If you have a wide variety of projects, it can be tempting to say "Well, that's one under control -- it only takes an hour or two to get it done now" and move on to something else.
Don't do that.
An hour or two of polish and delivery while you've got the entire problemspace loaded in your head becomes 3-5 hours after you've forgotten it, and it becomes 20-30 hours if you get a key personnel change or request for changed scope in a collaborator or client.
It means you don't get the joyful feeling of completion and momentum.
If it was a paid project, it pushes back getting paid, keeps your accounts receivable worse, and screws up your cashflow.
Oftentimes, clients or buyers will want a review and cooling off period after a job and before the next one, so it pushes back the date you can get followup work.
...it's just a damn bad thing.
Once you get over, say, 85%, it's time to push. Even if other things seem urgent, even if it seems like there's not much more to do, even if there's a million excuses or good reasons not to finish.
Finish. Push. Finish.
When you're close, finish. Terminator Mode.