Here's how I printed the parts for the watch. I used Slic3r to slice these. Find out more below.

Everything above except for the leftmost part (LCD support) gets printed with a 0.025 mm layer height. Initial layer height for these were 0.1 mm. The LCD support was printed with the standard 0.2 mm initial and layer height.

All the parts were printed with 100% infill. Setting it below that gives gaps just because of how thin each layer was. This could probably be remedied by increasing the number of perimeters (currently set to 2).

I enabled support material generation. Only the two parts on the left need support. I also had to uncheck the "Don't support bridges" setting. Anyway, support material removal is easy even without using the Prusa edition of Slic3r.

Here's what the support material should look like underneath that.