Chest / Core Workout,tips ?

[Aethernal]

Actually it seems like i cant work my chest/core as i would like to,my legs training routine comes to me really natural and i feel like i have natural predisposition for them,but as it comes to chest and core it seems like im doing wrong stuff or so,i just wanted to know what should be best routine,i mean,how many times-a-week,how much reps and stuff to workout chest.

I have from monday to saturday for workout but actually going monday wednesday friday,and doing some cardio in the off days (15'-40') any tips ?

[The Bear 79]

Stats? How long hav u been lifting? Wut r ur goals? Wut exercises / movements r u using 2 work ur chest & core?

[Aethernal]

Actually im doing 100lbs on both inclined bench press and declined bench press then i kinda lower the weight and do cables,and finally cross over on the bench.
I noticed i have a little difference ongoing between my triceps,whats the best exercise to isolate them both hmmm how to say...like,arm per arm ? if i work them simultaneously im feeling like my left one is getting really stronger thatn the right one,ill post some pics in the next days so u can judge.