Combining UIP:s with guild recipes is the best way to get high-end gear up to lvl 95, and also to craft cap-level items.
Guilding a character is a bit tedious, and it takes time. Plus, if you’re not VIP you have to buy yourself entry to the guild. But. See above.

Best way to get high-end gear up to at least level 95. Without even having to gather the mats. Because. UIP:s.
I have guilded crafters in all professions, and it is an investment of time and energy that I do not regret at all.
A character can join two guilds (an Armsman can join both Weaponsmith and Woodworker, and so on). My priorities would be Tailor, Jeweller and Metalsmith but then again… Why limit yourself?Check the lotro wiki for which professions are available for the different vocations.
Anyway. If you are VIP and want to guild your characters you better get started 😉
As soon as you reach the Expert tier you can join the guild, by talking to the Master of Crafting Guilds that you find in the major crafting areas. Do the little guild starting quest, and buy the recipes for guild rep clickies from the guild’s designated vendor.
How long does it take?
If you already have a character who can gather/farm Westemnet mats, it is possible to become fully guilded in less that four weeks. If not, well, it’ll just take more time. Or rep acceleration tomes and a bit less time.
You get guilded by crafting and consuming rep clickies.
Rep clickies have a crafting cooldown of 18 hrs / a bit less than 3 days / a bit less than 7 days, depending on how “advanced” they are. Make all you can, as often as you can.
How do I get that nice high-end gear?
When you hit a new tier in your guild rep, get the Improved guild recipes from the vendor in your guild hall. The output from these recipes are teal items, i.e. same results as the single use recipes but with guaranteed crit.
If you want to make a full set of armour you have to make a rep clickie for each armour piece – meaning a full set can take 7×3 or 7×7 days to craft, depending on clickie cooldown.
But not if you have UIP:s!
Just mark the Use Ingredient Packs checkbox in the crafting panel and blam! Teal items to your hearts content! In an instant! (or, well, because you’ve looted the Ingredient Crates in a very patient, non-instant manner).