3 rax is also somewhat of a cheese build with addons that is. i think you should stick to 2 rax and things like ALWAYS being on the map in tvp for example or pure marines vs zerg so you learn to do drops and spreads and what not
tough to train a skill other then just do whatever you can that is dif then what you are doing now and its tough to train a skill like spreading vs banes or dropping multiple spots at once while attacking with a main army since not all games get to that point or allow it
#1 way to get better is ALWAYS get into macro games