One of the best things to start with, when thinking about tuning your bike for more performance, is to start with making sure that engine is correctly adjusted.
Not all engines, even if they come from an assembly line, are the same. It is therefore important, that the carburetor is correctly tuned. Carburetors on factory bikes are set to perform well on all circumstances and within the measurement tolerance to what the engine is manufactured. (Which is fine for most of the time, but it is not the best it can offer)
You need to understand that carburetor tuning is a time consuming job, but it, if don right, is most satisfying. In the section Modify & Maintenance you will find some useful articles about carburetor tuning.