When do teams get in trouble in the NBA Draft? Well, let's put aside teams that pass on three perennial All-Stars and draft an overhyped foreign player, or teams that pass on a once in a generation talent for the big guy with balky knees. And let's also put aside teams that select two point guards with consecutive lottery picks but pass on two All-Rookie point guards.
Other than that, teams get in trouble when they ignore talented players to reach for a different player all because they think that a certain prospect fits a need.
Need is important, but talent should be the top criteria when putting together an NBA Draft Board.
What do I suggest: do what I do in fantasy drafts. Rank the players, and then put them into groups based on talent—group one is made up of the top players, group two, the second best players, and so on. When it is your turn to draft, look at what players are left in the various groups. For example, if your team wants a center, look for the best available center, but if you find yourself reaching down to group four when there are players left in group two, you are likely making a mistake.