Yes, keep the surfaces (and the entire darkroom) clean. This can be a problem, especially when using glass plates in the enlarger's film holder. Glass is great for holding the film firmly, but having to deal with dust and scratches on four surfaces can be frustrating, which is why I prefer to use metal plates instead of glass.
Another thing I do to minimize dust spots is to always wash the negative before enlarging. I have found distilled water with a splash of wetting agent works well. After the negative dries naturally, I inspect it under a lamp to see if any larger dust particles have remained on it, and if so, I carefully try to remove them. This can take a bit of time, and further washing & drying cycles may even be required, but in the end I find it easier than having to retouch a print full of spots.
thank you very much for your detailled comment. I know, the title is not that good, but I made it up very quickly, as I did not take my first picture very seriously. (I had it scanned by coincidence, and just put it into usefilm to see what happens...) Yes, the shadows... I admit that I was too lazy to do any dodging and burning in. I liked the effect and just left it as it was. Definitely a bit more detail in the pictures hanging on the wall (They impressed me when I was there) would be good. It is scanned from print with a simple agfa scanner. I don't like to correct the dust digitally, but I hate it if it's there anyway. What can I do in the darkroom? Just be careful and keep surfaces clean?
You shouldn't have titled it 'The Mirror', to see how many viewers would recognise that it is indeed a mirror :-) At first, I thought I was looking through a doorway. Only after I noticed the title did I realise the meaning of the face in the corner, and the fact that you can also be seen at the table.
I can't quite decide what to think about the tonality. On the one hand, I appreciate the mysterious atmosphere created by the overall darkness, on the other hand I would have welcome more detail in some of the shadows (the cupboard in the back of the room, and the people around the table). What I *do* know I like is the very clear rendering of the chandelier - that particular part of the image is very good just as it is.
I think it would benefit the presentation if you could get rid of the dust spots. Is the image scanned from print or from the negative?