It depends:
I usually set the ticket price at level 2 to 4 league and 5 to CL and cup. And then I increase it at each promotion by one. This way you get your stadium full, but it is no optimal policy. When you are doing good and your stadium is full increase it by one until you reach +5% support bonus. In case of doing badly decrease the price stepwise by one until you reach +5% bonus. When you don't care about the maximal possesion bonus and you go for money, you have to calc a bit to maximize <Nr of spectators> * <Ticket price per spectator> or search for one of the threads where a table is given.

In lower levels I don't give winning bonus, except very important late CL or cup stages with good teams. In higher levels of the match a winning bonus is crucial.