Traits, Feats, Spells, etc, all have a similar problem, people like specific options and will choose them again and again for their characters. People like what they like.
That said, if you feel they keep taking the same things again and again, you could do something like Wheel of Fortune's fix. In the past, for the final puzzle, everyone picked the same letters, R S T L N and E. Now, they give you those and you pick 3 more consonants and a second vowel.
You could approach the traits the same way. Give them one or two they always choose so they can pick something different with their extra trait. If you give them the extra, then adding some restrictions would be ok. For example, you can always have the +2 init trait, but for the extra trait you pick, it cannot be the same as the last character, or something. Or your two traits can't be the same 2 you picked last time, at least one must change, again, assuming you give them an extra for their favorite trait.
Or, why not let the player reuse their prior character from the last game? If they keep picking the same options, maybe they'd simply like to start over with the same character.
Cheers
