try to play with the defensive line (play deeper which could mean you'll be pressed super hard, losing the midfield battle / higher which would lead to deadly lobed pass behind your defense), and with the width. Usually, playing narrower tends to tighten up the defense, but sometimes, when facing potent wingers, you better play wider (at least for me) with individual marking from your fullbacks (require good marking / tackling attributes for them). It's all about balance, given the players you have.
Pacey defenders = play higher, they'll be able to cover the lobed pass mistakes quite often. Otherwise play deeper (but not too deep !) so they don't have that problem (or less).
I also noticed that tempo plays a huge part in both the offensive and the defensive part. Playing a high tempo will usually give you more opportunities as you take the opposition on the break, but it also often leads to stupid ball loss putting you in danger, especially when your team is rushing forward. Same goes for passing. The more direct you play, the more you are supposed to creat opportunities, but the more you lose easy (and dangerous) balls. On the opposite, playing a too short passing system would lead your carrier to be out of passing solution, being more and more pressed, and finally losing the ball.
Finally, check your defensive settings on set pieces. I personnaly concede a lot of goals from corners/free kicks and even throw ins due to poor defense on set pieces.
For your central midfields (or DMCs, don't know what you're playing), I can stress enough on the work rate and team work. This is absolutely needed, and you see a huge difference between an average and a good teamworker. They'll link up the play much better, and "sacrifice" themselves for the team's sake.
For your wingers, obviously look for high pace / dribbling / crossing attributes. They're the one that will create space (and goals by the way). To help in the defensive part, I personnaly love making them man-mark and tight mark the opposite full back, that way he prevents his opponent from rushing through your defense, and creating the deadly "+1" that often leads to dangerous situations.
Your AMC should be a technically gifted player (creativity, technique, passing mainly). I never been able to make him important in my defense, so can't help much with him in that part
for your striker, there is 2 schools : one with the little poacher, speedy and deadly, one with a big strong guy that will create goals opportunities for others. When playing with a big guy, you can ask him to press a lot, with his huge physical attributes, he can put a lot of pressure on the defense, forcing them to get rid of the ball, and helping you taking it back in the midfield for easy goals opportunities.
Hope that helps a little bit
