ok, to clarify, you will need to grind out the crafting xp somehow, and unless your server is different, most common armor and/or weapons don't sell that well. so the only way you will get higher level is to knock out a bunch of crafts, and sell back to the merchant for the cost of fuels, or craft a bunch, put on the broker and hope to make a mediocre profit (if any at all), or do the writs which will reimburse you the cost of fuels, give you status points, increase your faction standing with your crafting society, give you more TS experience, AA xp (for the first complete writ), and some extra coin.
overall, I would have to say that the writs would be the best way to gain levels (hell, even before the TS xp and AA for first completion, this seemed like the most logical choice). but that's just me.