How does a player craft a magic item?
Answer: They ask the DM how to go about it on a case by case basis & then do that.
There is no set way.
How does a DM create a magic item? What items, feats, etc. are used to create magic items?
Step1: Think up item.
Step2: Name item. (doesn't
have to be step 2)
Step3: Write down the details. (optional)
Step 4: Introduce it into play.
Seriously, I'm the DM. I am not constrained to making magic items via some formula. My will/whim is sufficient. Nor am I required to provide the players some formula so that they can replicate what I've made.
Yes, I am aware that this might not sound very useful to you as a novice DM. But the fact that the DM is all powerful & that the rules answer and bend to them, not vise-versa is something you need to learn, accept, & practice responsibly.
Help in this area would be much appreciated. Also, if you do respond, could you give specific examples of magic items, how they were made, where they were made, by whom, and how long did it take?
The wand of Sphinx detection - a not so serious item from a heck of a fun game.
This wand radiates magic (divination), but does not contain or use charges. Does not require attunement. Any class may use this item.
Description: A forked, barkless, stick about 2' long give or take.
How to use: Grasp the forks with both hands. Concentrate on locating a sphinx. Roll a d12 to see wich direction is indicated. 12=North. Proceed in that direction until you take a rest (short or long), then, if no sphinx has been encountered (or you want to find another one), roll again.
History: This is a 5e worded version of an item that one of my characters had in a Pathfinder game. I was playing a 1/2ling big game hunter who was in the region looking to hunt sphinx (never-mind that there were no sphinxes in that area). I was buying some equipment & an NPC tried to dupe me by selling me a stick with a Magic Aura spell cast on it.
I botched a Sense Motive/Insight check & paid 100 GP - for a stick.
It ended up playing an amusing role in the game though as I'd use it to get things going. I'd declare I was using the wand, roll the direction dice, & that's the way the party & I would head off.... And the DM just had to wing it. Or have us come across whatever he had intended. We jokingly called it the wand of plot detection.
The magic aura never did expire. Probably because the DM was amused to let it remain.
Time it took to make this "item" = Spur of the moment.
Formula = 1 part DM, 1 part Player roleplaying, & a never expiring Magic Aura spell.
(BTW; we never did run across a sphinx - though we were always heading towards one!)