You can output an Edit Link button to users that have the correct permissions by using [edit].
[edit]
Custom Text
When showing the edit link, you can also override the standard Edit text, like:
[edit text="My Custom Edit Button"]
You can also decide to only output the edit URL - for instance, to make your own custom link - by using: [edit-url].
You can also make a custom edit link by using:
[edit-link]My Custom Edit Link Text[/edit-link]
Adding or overriding attributes
You can override any attributes or set extra attributes to be used in the final <a> tag in any link data tag that generates one.
For instance, the edit link gets a btn as default class name, which makes it a button. If you want to override that, you can do:
[edit text="My Custom Edit Button" class="my-own-class"]
Or if you only want to override the class (and not the text):
[edit class="my-own-class"]