Originally Posted by EasyPeezy

I make my own starch. In a large bowl or pot, stir 1/2 cup cornstarch into
1 cup of cold water. Stir in boiling water (2 quarts for heavy solution;
4 quarts for medium and 6 quarts for light solution).

If you only need a small amount then half or quarter above quantities.
Sometimes I add a bit more water for the heavy solution as it gets
a bit too thick. You can try and adjust as you wish.

When the cornstarch solution is cool, I use a paintbrush to apply it on
my fabric (stir the solution often or shake if it's in a spray bottle).
Let is soak for at least 30 mins. If I don't have time to iron
I just put everything in a ziploc and put it in the fridge for the next day.
If it's too wet I roll the fabric in a towel first and iron on the wrong side
with a cloth on top so that the starch doesn't stick to my iron. When
the heat has absorbed most of the humidity then I continue to iron
without the cloth. Hope this helps.

By the way, I finally tried Mary Ellen's Best Press. I wasn't too impressed.
It's ok for small jobs. I think I'll keep using my cornstarch mixture. :-D