What should the underside of a bridge look like? I tried out printing a "bridge" for the first time using this Bridge Calibration model. The model creator suggests printing, tweaking settings, and printing again until it works "properly." 

My first try worked reasonably well, but the underside of the bridge is pretty rough and stringy. But I don't know what a "good bridge" is supposed to look like.



How smooth should the underside of the bridge be? Any suggestions for what changes I should make to my slicer settings? Here is what I have currently:



Here is a picture of my hotend on my Monoprice Maker Select Plus, as requested:
The idea of the part fan is to cool the plastic as quickly as possible once it is extruded in order to keep it in the correct spot. The slower that the plastic solidifies, the more the plastic will sag when printing overhangs/bridges. The stock part cooling fan/duct on your printer, Monoprice Maker Select Plus, is  not all that great and would probably benefit from an upgrade. 

As far as the Cura settings you posted, you should turn off most all of those experimental bridge settings. Your printer will still be able to print bridges without the 'Enable Bridge Settings' checked. The only one that would be useful is the the 'Bridge Skin Speed' since reducing the print speed effectively increases the air flow on the extruded plastic. More over you are turning off the fan for the 2nd and 3rd bridge skin layers which will cause them to sag even further.