If at any point of the cruise you stick the throttle in the blue zone, and make sure the needle of the throttle indicator also has its eye filled in blue, then it will manage the speed for you, with the aim getting you to <200km distance and <200m/s speed at the end so you can safely disengage. By design you still have to steer – you’ll want to swing around any massive objects in the path – and manually do the the disengage at the end. I have to give super-cruise at least some of my attention the whole trip or I will cock it up and overshoot.
As far as I can tell, if you set the throttle in the blue like that right at the start of the cruise, and then don’t touch it, it will always work. That’s not the fastest/shortest method, but it’s the simplest.
I tend to throttle at max until I’m 200 l/s away, and then drop back to the top of the blue zone. If near the end I wind up too slow – say 100m/s at 25000km out – I’ll thottle up for a short while, then bring it back down into the blue. That’s probably not the most efficient way either, but it works for me.
If I’m interdicted, it’s all power to the engines, full throttle, realign with my cruise target, boost, boost, boost until I’m out of mass lock and then re-engage cruise. That’s got me away from everything with only minor dents so far, although most often it’s just the Feds wanting to do a scan.
If you do drop out of cruise due to skirting a massive body too close, you might get dropped straight back out if you engage cruise again whilst aligned on your target – makes sense, the massive body was in the way, and its still in the way. The solution to this for me has been to engage cruise aligned in a completely different direction, let it run for a while to open the range, then swing back round to my target.
Finally, I always do a quick 180 flip on exiting a hyperspace jump to avoid quickly being pulled out of cruise by the star.
Hope that helps!