The Spirit Realm

light blue

Makes 0 difference. Chance of skill up is based solely on your current skill level and not the difficulty of the item your making, as long as you can get skill ups on it, any item you make has the same chance of providing a skill up.

Zethrir

I would cry if they made EQ tradeskilling like wow "tradeskilling"

If the RNG loves you, you win. If the RNG hates you, you lose.

Case A. If you have 400+ wisdom,* it doesn't much matter what recipe you do: you will have about equal chances for skillups on both success and failure. (For some tradeskills you equalize chance-of-skillup for success vs failure at lower wisdom than this; at wisdom 415 you have equal chance-of-skillup for success vs failure on every recipe in the game.) So do combines that are cheap, or easy to farm, or easy to buy, or don't take many subcombines, depending on your wallet and your patience.

Case B. If your wisdom is below 400, your odds of gaining a skillup on success will be quite a bit higher than your chances of skillup on failure. (The further below 400 you are, the greater the difference.) So you should pick recipes that you have a good chance of succeeding, in order to have the best chance of skillups. Once you have 200+ skill, you should succeed in making your product 95% of the time on most any recipe with a trivial within 20 points or so of your current skill: anything light blue, half the things that are dark blue.

After applying the advice for Case A or Case B, it becomes a question of the Random Number Generator deciding to give you a skillup. This is very very streaky and can easily get you to pull your hair out. A typical example from when I was mastering pottery a couple months ago: one week, 120ish combines, 1 skillup; same recipe, 10 days later, 120ish combines, 8 skillups.

The short version is: runs of 100+ without skillup are quite common, and well within the limits of randomness.

The long version, complete with full mathematical formulas, has been posted by tradeskill devs at EQTraders for a long time.

* I say 'wisdom' because we are shamans; it actually is the highest of (wisdom, intelligence, alt_stat). Alt_stat is strength if you are doing smithing, and dexterity if you are doing fletching.

Got my jewelcrafting to 102 last night, not much failure and the stuff sell back for rather
nice amount, if you buy a stack of silver and a stack of some gem total cost say 100pp
if no failure you proably get at least 80pp back(190 cha), compared to the 350ish pp Vs 18pp return
on a potion, and that was with low/no failure ( no wonder i run out of money so fast

No, although I wouldn't expect it to if it goes off the unmodded skill like I think it does. I think it was more of a fluke than anything else, but I thought it worthy of a mention at least.

I like the tradeskilling in anarchy online to, if you have the skill you succeed, it even tells you how much and what
skills(s) you need, good thing when you look for help with a combine.

Spending 16kpp to get 12 skill ups on alchemy makes no one happy