This is about the Master project oral presentation (10 min + 5 min questions), 
but most of what is written here here applies to any scientific presentation.


About the contents of the presentation:
The most important thing for any presentation or lecture is to decide who you are presenting for - as this will decide the contents and level.
In this case, the expected audience for the presentation is fellow master students. 

About the slides:
The first slide should have the title, name of the student and supervisors (including external co-supervisors). 
I generally recommend spending a little time on the first slide to give also some general background about the project.
The second slide is usually the Outline of the presentation (which may possibly be omitted for a very short presentation).  

The last slide is usually the Conclusion/Future work.
        (It has been popular the last 10 years or so to end up with a "meaningless" slide with the text “Questions”, 
         but I think it’s much better to leave the Conclusion slide for people to read and have as a basis for questions - 
         after all it's supposed to be the most important slide of your talk!
         You may let "Questions" or "Thank you for your attention" appear at the bottom of the conclusion slide (possibly with your contact details), 
         but you may also just say "Thank you for your attentions" (orally) - because asking for questions is actually the job of the session chair).

The number of slides depends on how easy the slides are to read. A lot of text is generally bad; figures are much easier to read.
One slide per minute is reasonable, so 10 slides for a 10 min presentation. It can be less - and it can be more if the slides are very easy to read. 

Any abbreviations which are not extremely common in your field, can be written in small fonts at the bottom of the slide. For example, RTO=Real-Time Optimization.
Similarly, any references should be put in small fonts at the bottom of the slide. 
It is recommended to number the slides so that people can ask questions afterwards.

About the presentation:
Try not to rush the presentation. Make sure you concentrate on what you think is the most important. 
I usually do not prepare in detail what I say, but other people like to have this well prepared. Both are OK.
In both cases it may be good to practice in front of the mirror, or just make a "mental presentation" by saying things inside your head.
I try to make one main message for each slide, and make sure that I say this clearly.

A bit about the feedback to the students afterwards:
It’s important that the students get to watch the video as soon as possible after the  presentation.
One possibility is that each supervisor/cosupervisor should record the presentation on their mobile and view it together with the students as soon as possible afterwards.
You can watch the video first (or most of it) and then ask the student what they think of themselves.
Sometimes they are critical about things are perfectly OK, so make sure you give constructive feedback on what they say and also on other things you think can be improved.
You should give feedback both on the slides and contents and on the presentation itself.