What and/or when should I craft?

Question

In Path of Exile, there's no gold (piece) economy. It is based on currency items which each have their own use and their prices are relative to themselves, and to the leagues in which they appear. What is the use of these currency items? Crafting.

Here is Grinding Gear Game's (the developer's) official list of currency items.
Here is the unofficial Path of Exile Wiki's article on Currency which includes more extensive information.

However, it's not hard to tell that burning high value currency on low-level gear is a...wasteful endeavour. It's nice to have good mods on low-level gear, but these items are not like the more eternally-valued end-game gear. People may suggest trading for the sort of gear that one desires instead of trying to craft it oneself. A good way to put it is that, largely, crafting is gambling.

I could go on, but I want to leave the rest to the answerer.

When should I wait and when should I create?
When should I pump it and when should I lump it?
When should I leave it and when should I conceive it?
When should I buy it and when should I apply it?
When should I ditch it and when should I hitch it?
When should I damn it and when should I spam it?
When should I whet it and when should I forget it?
When should I hone it and when should I disown it?

OK, I'm having too much fun.

Answer 1

Let me preface, I've played hundreds of hours on hardcore only so my views on crafting differ widely to softcore where there is no removal of items for the economy.

When should I wait and when should I create?

Wait for high ilevel items, lvl 56+ is usually a good place to start. The reasoning behind this is to make sure that your not wasting currency on low level rolls.

When should I pump it and when should I lump it?

Highly subjective, generally a good rule of thumb is to look at the possible max rolls, if you have a high potential max roll and you have a low actual roll then go for it.

When should I buy it and when should I apply it?

Easy buy currency low and sell high, play the market. Selling 1 exalt today might make you 1.1/1.2 exalts tomorrow (exchanging chaos).

When should I damn it and when should I spam it?

I assume your talking about high level items/uniques. In that case always watch the market, keep an eye out for new builds that rely on certain uniques and make your money there.

When should I whet it and when should I forget it?

Whetstones and Armour Scraps are dirt cheap (look for the 40% vendor recipe). Always max your items out. There's no need to be running around without 20% everything. Also worth noting that white items get 5% per consumable apposed to 2% magic (I think) and 1% rare.

When should I hone it and when should I disown it?

Hone always, discard rarely. In any league your characters will greatly benefit from your hand me down gear. Also there is a real market for twink gear if you have some nice pieces.

Hopefully that should help!