Very nice shot =)
Scratches can occur if you use a squeegee to remove water from the film, or when loading the film on the reel. (randomized scratches)
Scratches may also occur inside the camera (usually straight looking scratches).
I do my best to avoid dust during drying.
The method I use, is to run the water in the shower for 2-3 minutes to create steam. I usually put on the water when I start rinsing the film in the other room.
Then i dry the floor and put an oven inside the shower cabinet. (make damn sure the floor is dry before you do that!).
Then I hang the film inside the shower cabinet, along with the oven on low power (hot enough to dry the film quicker, but not so hot that it will damage the film).
- I've found that the quicker you can dry the film, the less time dust has the opportunity to settle on the film.
Once the film is dry, I cut them into 5-6 frame strips and put them into plastic sleeves, protecting them against dust as quickly as possible.
I always blow the negatives with canned air before scanning/printing, to remove any dust that may have settled while handling them.
Oh, and always use filtered water (buy a jug with a replaceable water filter, meant to purify water before drinking). Removing metals and grit from the water really helps avoiding specks that may even be embedded into the emulsion when it's wet.