This may sound silly but I think a great deal of client likes/dislikes are based on if they like/dislike the product not the logo design. Most clients I talk with have no idea why or what they like style wise
I ask them to look a logo they like, I then ask them to ask themselves "why" they like the logo, what is it about the logo they like. Most find this very difficult..
Patience and understanding most clients using crowd sourcing, well maybe not most but large number of them have been through marketing agencies and local designers as well as friends and family members with bad results or results that don't compare to what we can offer.