since its my area of expertise and interest.

with Brazil, youre going to be scoring the lionshare of your goals with Fabiano, Kaka and Robinho. set them up in good positions and figure out their strengths and weaknesses and apply them to your game.
i dont have much experience using Robinho or Fabiano (i have a ton against them), but for Kaka you ALWAYS want to try and get him in space. he's got incredible speed, good enough strength and a great shot. from my experience against Brazil, Robinho's got a great shot on him and Fabiano's a great holdup man in this game

master the curl shot. for me, this is the most effective way of shooting be it from distance or 1v1s.

idk how good you are at free kicks, but if youre not, go to practice mode and try and get 2 or 3 areas that youre pretty confident you can score from.

get a feel for the different types of crosses. with Brazil, you should be on the break a lot and a well placed cross can be deadly in those situations. i know of 3 different types of crosses, there may be more
1. regular (one tap of cross, hold for more distance)
2. short (two taps)
3. ground (three taps)
with all of these crosses you can either lead toward the goal, or aim toward the top of the box
I also use the RB when I cross, I'm not sure what exactly it does, but I get better results than when i dont. i think it targets a player though.

instead of the short pass to the close man, try a skip pass or a lob to someone who looks 2 or 3 passes away. it causes the defense to react more noticeably and opens up a lot of holes.

in 09, offense was fairly straight forward. 10 requires a little more cunning and guile. youre going to have to improve your vision (i find that to be another big problem for people who arent great offensively). i cant tell you how many times i've seen an opponent's player wide open that they had no clue was. try and focus more on what the players off the ball are doing. eventually you'll get to a point where you know what they are doing and you'll be able to pull off some smooth stuff.

most importantly, take your time. i think most people that suffer offensively get too impatient. pass the ball around the back. switch fields in the attacking third with the skip pass. anything to get a different look from the defense. balance patience with risk. sometimes you'll be able to force the opponent into a fuck up and reap the benefits.