I'm in the mood of replaying the game usually I use a guide for the replay to get everything the game has to offer. The problem here is obvious: Elden Ring is just to fucking big in comparison to other Souls games. Is there a guide that concentrates on all "essential" content? I mean all unique bosses, quests, events and so on. What I don't want is a description of all dungeons, enemies and items in the world.
I'm not aware of a guide like that but I do approach my replays in that manner. My replays usually take about 9-12 hours depending on various factors such as how much I get invaded. What I consider as essential is
-Content that have the stuff I need for my build for that playthrough.
-Essential mats such as bell bearings and seeds/tears. Unfortunately you will hit a bit of repeat content while collecting these things.
-All Shard Bearers: Godrick, Rennala, Radahn, Rykard,, dragonlord, Mogh, Malenia in addition to the mandatory bosses from capital and onward.
-All side quests, which will add all of underground and relevant the side areas in liurnia/Caelid/Altus.
-Access deeproot depth via sewers instead of gargoyles as I feel that access is more organic.
Doing content this ways leaves things like burial guard dogs, elite turned trash (like cleanrot knight in that cave) instances mostly, gladiators, etc. I do go out of my way to hunt down fights that I like like Bell Bearing Hunters and Crucible Knights but they are hardly "essential" I think. I feel like this keeps repeats to a minimum, or at least to my taste.