What's an upgrade?

New player here, just completed the campaign, but already feel like I’m slowing down because I spend too much time trying to figure out what’s a potential upgrade (and also what items to save/shatter.)

At this point the gear I’m wearing mostly has semi-decent affixes and probably reflects a couple lucky crafts where the Hope rune made my crafting potential go farther.

So when I look at what might be an upgrade, I have to start counting how many tiers of upgrades I’d need to add to it, then I’m checking if I have enough affix shards and runes, and guessing how lucky I feel on forging potential, etc,; which in total is too boring and slow to be fun for me. And if I do decide to go for it, it’s no fun when you end up having to shatter the item because you didn’t beat the one you already had.

Are there some rules of thumb to make all this go faster? If I can’t get to the point where I can “process” a full inventory of items as far as wanting to craft on, shatter, or sell in well under a minute this is not going to be a fun game for me.

(Yes, I have a loot filter that is at least weeding out the “no chance of being useful” items, it’s the ones that are in the “maybe” category that are occupying my time.)

First you should answer the question of whether you only want to play this character or whether you want to try other builds and if so, how many. The more builds the more you collect. I only ever dismantled the items that failed during the forging process. Others may do it differently. Of course, it depends on how long you have been playing or have played before. Over time, you collect so many shards that you no longer have to disassemble items. If you play according to a build template, e.g. maxroll, you can see which gear is needed with which affixes. If not, hover over your skills to see how your skills scale. Basically, upgrades regarding resistances, life, % life are always an improvement.
If you’re now at the normal monos, stay on the right path…58s, 66s, 75s, 85s and then the three 90s monos to unlock the empowered monos. On this path you should find gear for improvement and you will receive the first good blessings, which will help you.
As for the empowered monos, I’ve always farmed mainly the 66, 75, 85 and two of the 90s, again for the improved blessings. On lastepochtools.com you can find out which blessings can be farmed at which mono. Here too you will get gear and boss drops that will help you progress.