From what I've read, the water grain ratio is only "important" for the mash itself (the part where you rest for 60 min in the 150-156 range). It generally should between 1.25 and 2.0. This is so that you get proper enzyme activity while also dissolving enough of the sugars. As long as you are in that range, I don't think you'll see much of a difference in efficiency.
For batch sparging, I believe the rule of thumb is that you want the first and second runnings to be approximately the same volume. That typically means that you'll have a bit more strike water than sparge water, to make up for the amount of water absorbed by the grain or that gets left in the mash tun if you have dead space. (Alternatively, if that much strike water would mean too high of a water/grain ratio, you can add the extra water right before you mash out).
General tips I've picked up:
-Double check your volumes. Make sure you're ending up with as much wort as you think you are. I carefully measured this last time and was nearly a half gallon shy of what I thought it should be.
-Pre-heat the mash tun, it makes hitting temp a lot easier.
-Be sure to break up any dough balls when you add your grain and water. Dry grain doesn't convert.
-(For batch sparging) Give the mash a good stir after you add the sparge water, to make sure the sugars get dissolved. Let it settle for a few minutes before you drain.
Thanks
