UO Evolution has so much custom content and gear and ways to get them it's almost trivial to ask about certain pieces because in the end you're working for one- endgame item that fits into that slot, with a few possible temporary items to hold you over, but there's two slots that people can't really get by just a random drop, a quest, or even by donationand that's the ring and the bracelet
You can only get a decent ring and bracelet by one method, and that's farming, and farming, and farming, and farming til you're content with what you have, so the bigger question arises..what should you look for?
Depending on your class (or what you generally enjoy doing in uo)you want traits on your jewelry that you can't get elsewhere or that cannot be socketed
to lay out a few templates for example
a swordsman's best friend would be a bracelet/ring with 15 swords and 15 tactics. why?
because there are no augments for swords and tactics in the game and raising those skills are completely based on your gear alone
yes a 15 swords/healing, or 15 tactics/anatomy, or swords/parry or any combination are very nice and can fetch a high price
but you can socket things like healing/anatomy/parry into your gear, meaning that's possibly a loss of 15 unattainable points elsewhere
each piece of jewelry has 5 total possible lines of skill.
meaning if you found a 15 swords and tactics ring, you can socket another 15 total skill into it, and add parry or anatomy, or healing, or animal lore, or whatever you desire
as far as magery goes, magery and evaluating intelligence is your best bet
and for taming- you would want animal taming and lore (lore is socketable but in this case for breeding purposes it does more than veterinary. its contradictory of what i said earlier. but that's why its bolded)
some hybrid classes such as mages may want to have tactics on their jewelry due to the 175 required for a successful spike shield. most gear that gives magery and eval has no tactics on it, meaning you're relying on jewelry solely to get that skill
when it comes down to the gist of it, the most valuable jewelry you can find will all fit into a single basic class, and have skills on it that are not socketable elsewhere
don't rule out things like bushido or focus either
it might not seem valuable to you, but to another player, it may be worth millions
**but necromancy is completely worthless just a heads up it has no determination in debuff strength with necro spells or damage, that is purely spirit speak
if you find jewelry and have a question on it's worth, feel free to [pm cain in game and i can help you appraise it. until then, good luck finding jewelry evolution.