is it advisable to file soldering tips to a fine point? If so will this affect the conductivity of heat? Finally what is the best way/tool of filing the tip?

It depends on what type of tip you are using.
Some soldering tips have a coating which will be destroyed
if you start filing it. If the tip is simply a rod of copper then you
can file as much as you like.
Filing would be done to remove layers of oxide/corrosion/dirt/residues of soldering flux or to re-shape the tip when it has been corroded so badly that there are craters in it. A normal file will do the job, preferably one that is intended for smoothing metal (the type were the grooves are not crosshatched).
You could also file the tip to produce a special shape or make it small
enough for the intended soldering job.

The transfer of heat depends on how well the soldering tip makes thermal contact with the workpiece and this depends on how clean
it is (there special sponges to wipe the tip on (kept wet) and also some kind of brass or steel "wool").
The heat transfer is usually improved by adding a little solder to the clean tip before applying it to the workpiece, if the workpiece is also clean the solder will then make good contact with the workpiece.
Don't use the tip to transport solder to the workpiece since the needed flux will then evaporate before hitting the workpiece, always apply solder to the workpiece. If the solder melts when applied directly to the workpiece you know that the workpiece is hot enough.
/ Robin