I tried making a few things pieces of jewelry from the new ML gems including white pearl and they seem pretty crappy really. Do they sometimes come out better or is there any way to improve them? Or do people want them just because they're kind of rare? (I hate having resources that I only sell and never use. I think that's a pretty boring way to play the game).

well some of the jewels can be nice.. ecru citrine can give you Enhance Potions

Blue Diamonds, can put Mana regeneration on jewels.. so it depends on the other mods on the jewels you make.. of course I'm talking 1000's and 1000's of jewels made.. giving you one great piece of jewelry

Pearls - 6 property possibility, up to 100%. VERY nice.

Of course, the pendant of the magi is beautiful.

And as lemon said, blue diamonds, ecru citrine. Perhaps an undervalued jewel would be the fire ruby. I can attest that fire resistance is in vougue because of the prevalence of necro warrior templates. Until recently, a bracelet made with this was a keystone in my template.

So what does Enhance Potions do? Does it just make the potions you iuse work better? Or does it do anything for alchemy, i.e. actually making better potions?

And I take it that every piece of jewelry then is completely different?

I made a Pearl Bracelet that is:

Mace Fighting +12
Int Bonus 4
Night Sight
Enhance Potions 10%
FCR 1
LRC 10%

Is this any good? Typical? Crappy?

(Sorry to be so ignorant, but most modifiers are still kind of meaningless to me. The only one I've managed to really do much with so far is LRC because I got tired of running out of regs).

And I sure wish I had that Pendant of the Magi Recipe... (Not to mention the Scrapper's Compendium)

the bracelet you made.. I'd say is crappy.. some would say typical..

Enhance Potions provides a percentage above the normal effect of the potion.... so say at 50% EP you sucked down a greater heal which usually heals for 30hp... it'd heal for 55

Enhance Potions only works for the drinker of the potion, does nothing for the alchemist making it or the potion itself.

Erm.... surely it would heal for 45?

Pale, have you looked at the item property charts (given that linkin a couple of rpelies to you). They are color coded for properties AND intensities that are good (You are NOT alone in confusion over properties, which is why I made the charts (for ME!)). That should help some. I have color coded the intensties above as they would appear on the chart.
Also, refer to the thread in the Common FAQ Forum called "What makes good loot".

As to the brace above, all the intensities are at the middle to low end. Has ALOT of properties, but none great.
When it comes to jewelry, combinations are the real money maker.
For instance, one form of a PvP dream jewel would be
FC1
FCR3
LMC 8
HCI 15
DCI 15

A dream mage jewel would be
FC1
FCR3
LRC20
SDI 12
LMC 8

To add to what BG said, in addition to being low/middle in properties, it's WHICH properties that are the deal breaker. That piece of jewelry is basically junk to most folks (not trying to be harsh...hope you don't take it that way). With the Mace Fighting bonus, strength or dexterity bonuses would be better, as would a higher enhanced pots level. The LRC is only very rarely needed with a dexxer template, so that is pretty much useless on that jewel. The faster cast recovery is ok, depending on one's template and the need for casting. In that particular bracelet, something with Skill bonus, plus dex/strength, plus higher enhance pots, plus HCI/DCI and then maybe FC/FCR would be far more desireable to most folks. LRC and Night Site not so much as that can be found and incorporated with armor pieces if necessary. FWIW.