Similar album covers

So, to create an album cover in a genre, you have to assess the genre and various principles involved in preparing an album art for the track.

Firstly, great graphic pieces are often successful. The sort of image that would make a great poster, or phone background. Usually these cross the border between trad-tattoo style drawing or obscene, macabre or obscure cartoon drawing. Something weird that stands out as visually impressive, essentially.
         

Secondly, artwork that involves a symbol is always effective, as people often memorise or idolise it. Again, it may become a background, or something that someone will draw over and over again, or enjoy wearing on a t-shirt, or a tattoo.

Some bands merely use their name, against a backdrop. Simplistic but artistic, without all the graphic work involved. This is most effective if the album is self-titled, as it needn't use a second heading (album name, etc) So, featuring just the album art is more detailed and perhaps says more.

The band may also have an established fan base already, so they merely have to throw out their logo or a recognisable feature for people to buy it. This links back to the symbolic element.

However, some albums go for the all-out random or irrelevant in terms of their album art. Something that has no literal meaning, but may be pragmatic, relying on the audience to dwell upon it. It may have no implied meaning through their songs or album, or even name, but  is either provocative or controversial in someway.

Of course, sometimes its simpler to just show the band, be it them, or them glorified in someway. Often strong or contrasting lights or colours make for a great cover.

However, sometimes the most simplistic but irrelevant are the most effective. Less is more is often a rule that can apply to album art.

Often, the most bizarre ones can end up confusing the consumer, and creating an over-crowded cover photo can ruin the credibility or appeal of the entire album. Going out of the ordinary with something visual can draw the attention away from the audible.

Going back to the 'random' or 'irrelevant' or 'provocative' element, often an album art can become the most famous or memorable element of the production. Nirvana's Nevermind album art is instantly recognisable for example.