Over the years, I've seen several things that students make repeatedly that had to be "corrected". I know I've made some of these things myself when I was a student. I've talked to a number of professors, and they too have commented that these things that students do are quite common before they learned not to do it.
One of the most common ones happen when they have to plot a graph. Inevitably, physics students will have to produce a report that includes graphs. This often continues into graduate school where they either will have to produce graphs for publication, or for presentation.
Inevitably, when they first do this, the most common thing they failed to do is to resize the labels and the axis titles. What they typically will do is simply to use the default setting of whatever data plotting/analysis software that they were using. For example, the graph below was done using Origin, and I simply used whatever the default settings that the software had:
My graduate students meet with me and a couple of other faculty members weekly to discuss the work being done. During these meetings, the students often present their results and whatever else that they did, and inevitably, there will be a few graphs. The new students ALWAYS, never fail, did what I had just described. Most of the time, we could hardly see the axis labels and values on the screen because they were so small. It is almost a right of passage that one of us will have to tell them that they have to resize these things and make them bigger. If they forget to do this when they're submitting a manuscript for publication, then they will encounter a comment from the editor of the journal about resizing the labels.
Eventually, they learn, as with other things, as part of their process of becoming a scientist. In the scheme of things, this is not a big issue, but I find it amusing that almost every single student that I've encountered started out by doing this identical habit.