I like the flow chart for deciding if it's a boys toy or a girls toy:

Do you use your genitals to operate it?
Yes > it's not for chidren
No > Boys and girls can play with it

As for traditional gender limited toys, we mainly have toys marketed to boys but my daughter also has dolls and all the kids share them. My daughter tends towards the bikes and the dolls, and my sons tend towards the dress ups and action toys.