I just went through the process of adding follow buttons for my social media accounts to my website (WillCoffin.com) and thought it would be useful to compile a list of all of the resources I used. They are not the prettiest all lined up next to each other, but it works for now until I have more time to mess around with the CSS or create my own versions.
Spotify: Spotify Follow Button Generator
Twitter: Twitter Button Generator
Linkedin: Linkedin Member Profile Plugin Generator
Facebook: Facebook Follow Button Generator
Pinterest: Pinterest Widget Builder
These are really the only ones I care about right now, if something else pops up I will do my best to update this list.