I use this tool to quickly look for album art on this site which (in my experience) yields the best overall results and has better performance than AlbumArtDownloader for example.
Name: Cover Lookup
Path: C:\Program Files\Mozilla Firefox\firefox.exe
Parameter: https://covers.musichoarders.xyz/?artist="$replace(%artist%,'"','%22','#','%23','$','%24','&','%26')"&album="$replace(%album%,'"','%22','#','%23','$','%24','&','%26')"&country=de&sources=deezer,tidal,applemusic,itunes,musicbrainz,amazonmusic,vgmdb,bandcamp,gracenote,amazon,lastfm,spotify,discogs,ototoy,qobuz,soulseek,soundcloud,bugs,flo,linemusic,recochoku,netease,kugou,metalarchives,gaana,fanarttv,melon
You can use different browsers instead of firefox in the "Path" section, replace "&country=de" with the ISO code of whichever country you want to see results from, add &resolution=[size]
if you only want to see images equal or greater than that size, remove sources from the list you don't want to use etc.. The order of sources within the parameter defines in which order they are displayed on the site. If you want to see the discogs result first, put it in first place in the , separated list.
I've set it as my first tool so I can press strg/ctrl+1 after selecting a track to search for art easily and quickly. Maybe someone else will find this useful as well.
Edit: I just did some further testing and this only works well for artists and albums which don't contain reserved characters like '&' (which has to be replaced with %26 for it to work). Is there an easy way to encode %artist% and %album% to be compatible with URLs?
Edit2: Tested reserved characters and added those which broke the links in 2 replace functions. If you find a character I have missed that breaks the URL, let me know so I can edit the parameters.
Edit3: As suggested by Florian I've adjusted the post to be more of a tutorial and less of a question as to where to post the tutorial.