What to set the +/- rating as for best improvement?

Currently I have it set at 

-50, +200

i guess that ensures mostly i face better players, but not so often that i keep losing every game

Ive wondered about changing it to just 0, +200---- what do you guys think

You would usually want to play people whose skill levels are slightly higher than yours. What you have set is already good, because most of your games would then be against the people slightly better than you. Then, you might come across a lower-rated player, with whom you can test your new learned skills you may have learned while playing the higher-rated people.

However, I would make it so most of my games would result in a 0 or +1 in rating change if a draw is achieved in those games.

That makes sense, Winchen. I have mine set to -100, +400, but I accept games against players lower rated than that, mostly because there just are not many games available if I don't.

I refuse to play opponents who don't play anyone lower rated than themselves. If that's their philosophy, it should also apply to their opponents.