I let the fabric absorb the starch for at least 30 mins then use a dry iron.
By the way, I use homemade starch which is more economical although
Best Press sounds like a good option when I'm in a rush. :-D
If I run out of time I put the fabric in ziplocs (separate dark and light just
in case) and put them in the fridge until I'm ready. If the fabric is too wet I
lay some towels on the table (put some plastic tablecloth underneath to
protect the table) and I blot the excess starch then press. I find the fabric
has to be slightly damp, not wet, otherwise it will stick to the iron and make
a mess. I've also pressed between cloths to absorb most of the moisture
then press until dry.