The Real Madrid forward was widely praised after his superb curling strike into the top-left corner put Spain in front in their Euro 2016 qualifier in Huelva.
However, Del Bosque opted to single out the former Malaga man when outlining areas for improvement.
Del Bosque labelled Isco as "excessively elaborate" after the game and the 22-year-old is eager to heed his coach's words.
"I like to enjoy myself and perhaps I erred a bit trying to play attractively but the important thing is to learn from the criticism," Isco said.
"We have to get used to both praise and criticism.
"One day you are up, the next down and I have to remain calm, work, help and learn, that is the most important.
"Each game helps me to continue improving which is what I want. I want to improve in defence, on the ball, score more goals, I never want to get tired of improving."
