Blocking
There are many differendt ways to block. But I am going to share with you the easiest.

If you have a many  pieces to put together. Block them seperately before joining.
(Much, much much easier)
Now. Get your iron, a towel, maybe two towels,  and your ironing board.

First, shape your piece.  Pull and tug as necessary.

Then, wet the towel and wring it out.  Place the very damp towel on the board and press with the hot  iron.
Whoooa. The steam from the towel presses the piece.
You just blocked.
Golf clap.
(I have done this in a hotel room and a bed. Emergency gift. It works anywhere)