@Craig-4 Not claiming that this is the best way, but this is how I do it:
Route end point: I put mly end points on the road fairly close to my destination (read: hotel). This way I am sure that routing will have stopped when I arrive which avoids a few annoying things with my GPS.
Route starting point: never at the hotel because then the GPS may miss it and keeps sednign you back. Very often, I put my route starting point on the first main road outside the city where I stay. That may be several kilometers away from the hotel. This way I can give my GPS the freedom to calculate the optimal route to get out of the city and pick up my route when the odds of having a roadblock are minimal.
Your second problem. Your GPS may be doing the correct thing. It is calculating the most efficient way to go to nearest point, and in many cases this does mean turning around.