I bought a 0.2mm Micro Swiss nozzle for my 3D printer after the provided 0.4mm wasn't achieving the resolution I required for my up and coming keycap printing job, and I was having a painful time getting prints to come out cleanly or stick to the bed for the first few prints.
After playing around with the settings and generally getting frustrated, I found that raising the printing temperature by 10-20°C and tweaking the some of my slicer settings I found something that worked for my Flash Forge Pro.
Nozzle Diameter: 0.2mm
Extrusion Multiplier: 0.9
Extrusion Width: 0.2mm
Primary Layer Height: 0.1mm
Perimeter Shells: 4
First Layer Height: 110%
First Layer Width: 130%
First Layer Speed: 40%
These settings on top of a freshly leveled printing bed gave the print a rather strong grip to the printing bed that insured no curling would happen.