I have a spray bottle, about a quart, and put 2 tablespoons of liquid fabric softener in it and fill the bottle with water and shake it well, until it is all mixed. I use warm water as it mixes better. If it is not all used, in time it does get kind of gunky looking. I just dump what is left, wash the bottle real well and start over. It does keep for several weeks. Of course, I could make less, but I have been using the same dollar store container of fabric softener for at least four years, so do not really feel the need to be less frugal.
Before I did this, I used to hang wrinkled items in the bathroom while taking a shower. The steam would relax the wrinkles enough that I could smooth them with my hands.
The only time I use my iron is when I sew.