I recently started doing finger press (or using a wooden press stick) during the block construction. Then I give it a firm press with the iron when the block is done. Using steam depends on how well the seams behave.
I have always used a dry Iron if I need steam I use a spray bottle. Ladies aren't spray bottls great! I remember using a sprinkle bottle when Ironing cloths. I still have mine.
I use steam but make sure to press - not iron! I think that is where the stretching comes in. Also do not move the fabric until the heat is gone so no stretching from that.
No steam but sometimes I dip my finger in a little bowl of water and just
dab those pesky seams that don't want to lay flat then press or I use a
small piece of damp cloth on the seam.