I use chain tensioners and I keep my chain pretty tight, so that at the middle of the span I can wiggle it with resistance about 1/2" up and down.
I use EAI cogs and I centered my chain ring according to Sheldon Brown, and I have no tight or loose spots in the spin.

When I get a new chain I experience an initial stretch during the first two weeks, but after making an adjustment for this initial stretch the chain kinda settles in and I get a couple of months out of it that way.
I ride in an environment that has a lot volcanic ash on the road and even with dry lube I need to clean my chain at least once a week.