Start a new season. Before anything else, go to "Free
Agents", and sign the highest rated free agents you can find,
such as Alonzo Mourning (70), and Karl Malone (69). Replace good
free agents similar to them with your weaker bench players. With
more high rated people on your team, you will be able to make
more trades to get very good players on you team.
In season mode when trading, look for teams with one or more spots
available on their roster. You can trade two or more lower ranked
players for one of their higher-ranked people. Keep doing this
with teams. You can then get even better people on your team.
Using this and the previously mentioned "Better season mode
team" hint will not be as effective in dynasty mode, because
of the salary cap. However in season mode, it does not matter.
By using both hints, it is possible to get a team with Allen Iverson,
Shaq, Yao Ming, Peja Stojakovic, Manu Ginobili, and other decent
players.
There is an easy way to change a horrible team into a great team
to use in dynasty mode. Trade all the bad players to other teams
for great players before you begin the dynasty. For example, before
starting dynasty mode with Atlanta, trade their starting five
players for Shaq, Duncan, Mike Dunleavy, Kobe, and Gilbert Arenas.
After doing this, save the settings, then begin the dynasty.