For use with {{Infobox album}}; use this template in a "Misc = " section like this:

{{Infobox album <!-- See Wikipedia:WikiProject_Albums -->
...
| Misc          =
{{Extra album cover
| Upper caption = 
| Type          = 
| Cover         = 
| Alt           = 
| Lower caption = 
| Border        = <!-- optional parameter, type "yes" here to add a 1px border to the cover image -->
}}
}}

For use with {{Infobox single}}; use this template in a "Misc = " section like this:

{{Infobox single <!-- See Wikipedia:WikiProject_Songs -->
...
| Misc          =
{{Extra album cover
| Upper caption = 
| Type          = single
| Cover         = 
| Alt           = 
| Lower caption = 
| Border        = <!-- optional parameter, type "YES" here to add a 1px border to the cover image -->
}}
}}

Important: When using this template, please ensure you comply with the non-free content criteria. This includes not using multiple non-free images when one would suffice.