There are still some things that are worth a salon trip and paying for properly.
Brow shaping can be extremely difficult and is an art which is best performed by experts, and they are also able to look at your face objectively and use symmetry. Whereas, like with cutting hair, if you start cutting or trimming little bits off you will end up with nothing left.
Having your teeth whitened at home using a kit can cause damage with the mouth guards they provide as they are just a standard size, they can cause gum damage and can leak. Although they are getting better they are not as good as the real thing, and toothpastes only remove surface stains.
Lash extensions, some lash growth serums and other products do work, but they are still not as good as the long lasting natural looking salon applied extensions.