With regard to your pressing/ironing...prewashing, I think, makes a difference. You have not stated if you do this or not. Otherwise, imo, the highest setting on your iron; some spritz of water and/or starch are the key elements here.
Bedding sizes...well, that gets all of us! If it's for your bed, you can do measurements and plan accordingly. If it's a gift, well, you can just hope for the best. My personal opinion..it really depends on how you make your bed. I like a tuck and a pillow cover. Granted, this DOES NOT regularly happen in my house! I don't even have a quilt on my bed as we have dogs that sleep with us and I don't want the 'nesting' thing to happen to one of my quilts.
If it's for a recipient, try to find out how they make their bed! If the 'pillow tuck' thing is their preference, add some some coordinating blocks to the top of the quilt. I usually do the sheet; blanket(s) thing, and leave things fairly 'casual' so an extension to the top of the quilt would not be necessary.