City boss Roberto Mancini has been critical of the winger's attitude in the past, especially after he broke into the England team. Johnson, however, has nothing but praise for the way his boss has brought him on in the 10 months since he left Middlesbrough.
He said: "From the moment he came in the manager he has helped me a lot. He has told me all sorts of different things."
Johnson added: "He has seen a lot in his career and all his advice is starting to show a little bit in my game. It is about running off the ball, my movement and stuff like that and when to get a shot in.
"It is also about not wanting the ball at my feet all the time, and maybe trying to get in the box and on the end of a few more crosses."
Johnson scored a superb individual goal in the victory against Salzburg which helped secure the club's passage into the knockout stages of the Europa League.
The former Middlesbrough man, 23, is now hoping to retain his place in the side to face Bolton on Saturday and make only his sixth start in the league this season.
Johnson continued: "I was happy with my performance against Salzburg and really pleased with my goal. Hopefully a bit more of that will come in the next few weeks.
"I played a bit more on the left, but I am comfortable on either side and it was a slow tempo which gives you space and time to enjoy it."
Johnson's goal came after a brace from summer signing Mario Balotelli, which took the 20-year-old's tally to five goals in just four starts. Balotelli is expected to link up with Carlos Tevez against Bolton after the club captain was rested in midweek.