Optimize lab report grading rubric to minimize grading time
When I was teaching physics classes in grad, grading got easier after creating a key (or rubric) that was really concrete. By creating a specific set of things to look for, grading took less time and students were happier with their grades.
Here is what worked for me.


Explaining figure etiquette: axis labels, include units, have the data points take the majority of the graph area.
Communicating the expected details: clarity of answers, showing work, including the data sheet, etc.
Giving examples of deducting points for poor quality.


I found same-day grading took less time (since the material was fresh in my mind) and created a great deadline for late work. I accepted work for full credit until I grading was finished; afterwards, I awarded late labs 50% (without grading).