Fixing the buffet line
Here's the obvious way: Watch people waiting to go through the line. Find the spot where the line slows down, where there's a gap between one person and the next. That's the spot that needs attention. Add a few spoons, pre-portion the item, remove a step.
Here's another way: Schedule how people enter the line. By managing the flow, you'll relax the participants and eliminate rush times.
Here's a better way: Pull the table away from the wall so people can walk on either side, thus giving your throughput a chance to practically double.
If you work on an assembly line, it's likely that someone has already thought about this.
But many of us are soloists, or do dozens of tasks a day. It's not as easy to notice where the bottlenecks are, so we have to look for them.
Have you considered the high cost of task switching? It probably takes you a little while to stop doing one thing and start doing another with efficiency. What happens when you switch less often?
Also: Consider the sprint test. If there's a task that comes up often, challenge yourself and your team to, just this once, organize and prepare to set a world record at actually completing this task. Get all the materials and processes set in advance. Now, with focus, seek out your most efficient flow.
Obviously, you can't do this every single time, but what did you learn? Steal the best parts and add them to your daily practice.
Is there someone who is more productive at a given task than you are? Watch and model. Even the way you hold the scoop, reach across the table or move the mouse is sufficient to change everything.
One last thought: Inspections are essential to maintain quality, but re-inspection is duplicative and slows things down. Where is the best place to be sure you've done the work properly? Do it there and then, and not again, and not five times. Organizing to build quality into the process, with steps that check themselves, is far more productive than constant task switching and over-inspection.