After removing the laundry, take your t-shirts and stretch them yourself, one by one, when they're still slightly wet. Grab them with two hands symmetrically, stretch horizontally, moving your hands down along the shirt. Do the same vertically, and with the sleeves.
Do not use a machine dryer, just a regular standing dryer like [1].
Put your t-shirts carefully, symmetrically on the dryer, and once dry, put them on a hanger. If you follow this, you will not have to iron them at all.
Source: been doing this for 4 years and I didn't touch the iron since. I have all t-shirts 100% cotton (though I buy only high-grammage ones) and they all seem brand new and ironed (the only exception being one particular brand whose collar looks bad unless ironed, I stopped buying that brand). YMMV of course.
[1] http://ecx.images-amazon.com/images/I/41oWjx2Q-mL._SY300_.jp...