I've quilted for 20+ yrs and also taught classes. I do some of both, I finger press some blocks and others I press as I sew, depending on construction. I do a lot of strip & chain piecing so I can press a lot at one time
The MAIN thing new quilters need to know is to PRESS - not IRON !! You're NOT ironing a shirt ... Ironing (back & forth) distorts ANY block no matter how well sewn. Remember - PRESS don't IRON :)