Luckily, I never had to convince my wife to go WP as that is all she has had since entering the smartphone arena. My kids were another story but they did eventually see the light.
My wife's favorite accessory is the wireless charging stand. Also do a search for wholesale cell phone accessories. Not sure if I can link the site but you should be able to find it. They have accessories for really cheap. I bought two rugged cases, two 'blingy' cases and two, kinda green, glow in the dark skins, a car mount and two desk stands for about $30. They are made by Empire and are good quality. I use the rugged case and it works really well and even has a pop out kick stand.
My wife, my daughter and I have the L920 and this is the first phone I have not used a screen protector on and none of them have any scratches on them. That is saying a lot when talking about a teenaged girl's phone.