I recently realized that, when it comes to crafting, I always make the same mistake in every MMO I play. At first, I always choose a profession that makes armor or weapons.
This is a predictably bad choice. Armor and weapons are almost always given as loot. Indeed most people will level up and gear out from quest rewards. So as a gear crafter you are left with two outcomes. Either your crafting always lags behind your level, and you never actually craft usable gear. Or you keep your crafting up to date and end up vendoring your quest rewards.
Then when endgame comes around, because no MMO implements the "crafting BoP gear for other people" verb, gear crafting really does not happen.
Essentially, when you pick gear crafting, you end up in competition with the game itself. And because not everyone is a crafter, the game usually wins.
The much better strategy is to pick crafting professions which do not compete with the game. Examples are consumables, enchantments, glyphs. Things where the crafter, and not the game, supplies the vast majority of items. These professions tend to be much more useful than gear crafting, because there are always other sources of gear.
Ironically, I realized this before I started GW2. Yet when I looked at professions, I still picked armorsmith and weaponsmith. It's a hard habit to break. The lure of being a master craftsman is strong.