For you guys that are flying the smaller ships (eagle, vipers etc), Jump Range is a big issue especially when crossing the spiral arms.
How I did it in my Cobra was to go UP the galactic plane (or "down" works too) about 100 LY or so... you'll completely bypass the Aucoks sector of brown dwarves and will have a much easier time crossing the arms with a 20-LY or less jump range.
Being away from the central galactic plane where "everyone else is" also helps the Galaxy Map plot routes quicker - there are less stars to worry about, and less need to "optimise" your route at 99%. When I did my run I have never had a route plot for longer than 15 to 20 seconds. Never. In fact, nearer to the Galactic core (1500 LY), the lowest distance I'd needed to plot was 300 LY to get a reasonable time (less than 30 seconds). After that, my final 600 or 400 LY plot was an instant-plot direct to Sag A*.
So I've never encountered what some have reported here - 15 minute plots, single 20 LY jumps, manual jumping etc... I never needed to do any of these.
Just putting it out there in case someone actually reads this