When you initially unlock Illustrious training the recipe for Embersilk bolts will already be gray to you. This recipe is learned at 425 and is no longer useful by 450. Old recipes that can be used are the Glacial Bag and the Ebonweave/Moonshroud/Spellweave Robes, which are yellow at 450 and change to green at 455. I don't know that I would actually use these myself, but you can if you don't mind crafting something that may not sell.
Most of what you'll make through 500 skill is green (uncommon) quality gear. After that the only options are blue (rare) quality PVP gear. If you have the ability to collect some volatile water or fire before you start crafting, you can add better items to your repertoire. I noticed that there are a pretty good variety of items that give multiple skill points. They require more materials of course, but you would end up with something worth selling by going that route. For instance, one of the first recipes you get at 450 is the Enchanted Spellthread, which uses the same number of bolts as the green items and gives 3 skill points instead of 1. The downside is that it also uses 6 volatile fire, so it's not exactly cheap either. This is the sort of choice you'll be making on all of the various multi-point recipes. It's usually not a matter of just higher components, but higher components + uncommon components.
A couple of other things you should know about leveling Tailoring. Recipes that give multiple skill points only do so while the recipe is orange to you. Once it changes to yellow, the multi-point feature is gone. So if you're going to use it, use it. Also, the self buff recipes will all be gray when you learn them. I don't remember how this was for WotLK, but you won't be able to get any freebie points by enchanting your own duds in Cataclysm.
Here's my suggested recipe progression to reach 525 Tailoring:
450-455: Deathsilk Belt or Deathsilk Bracers | 10 bolts of embersilk
455-460: Deathsilk Shoulders or Deathsilk Boots | 15 bolts of embersilk
460-465: Deathsilk Leggings | 15 bolts of embersilk
465-470: Deathsilk Cowl or Ghostly Spellthread | 15 bolts of embersilk or 9 bolts of embersilk + 18 volatile water
470-475: Spiritmend Bracers or Spiritmend Belt | 20 bolts of embersilk
475-480: Spiritmend Boots | 20 bolts of embersilk
480-485: Spiritmend Gloves or Spiritmend Leggings | 20 bolts of embersilk
485-500: Spiritmend Robe | 90 bolts of embersilk
500-505: Emberfire Bracers or Fireweave Bracers | 30 bolts of embersilk + 20 vol.fire + 20 vol.water or 30 bolts of embersilk + 15 vol.fire + 15 vol.air
505-510: Emberfire Shoulders | 30 bolts of embersilk + 15 vol.water + 15 vol.fire
510-515: Emberfire Belt(2) + Fireweave Belt(1) | 26 bolts of embersilk + 11 vol.fire + 8 vol.water + 3 vol.air
515-521: Emberfire Gloves or Fireweave Boots | 30 bolts of embersilk + 12 vol.water + 12 vol.fire
521-525: Emberfire Boots or Fireweave Gloves | 40 bolts of embersilk + 16 vol.water/air + 16 vol.fire
Currently the Emberfire Belt at 510 is giving 2 skill points, while the Fireweave Belt gives only 1 skill point, so I went with 2 Emberfire and 1 Fireweave Belt. This may be a bug, so be prepared to make five belts at this stage if necessary. The same issue is involved at 515 where both new recipes were giving 2 skill points. I made three items and got 6 skill points, which cut the next step down to four items instead of five. Again, not sure if this is a bug, so be prepared to make five of each of these items.
Something you might be willing to substitute in are the various bag recipes you'll learn. Crafting the new bags will get you 5 skill points, so if you have the materials it may be worth it to you. I didn't include them here because you'd have to use another profession to get those extra components. You can also use the Dreamcloth recipes for extra skill points between 500 and 525, they all remain orange until 525. I believe they are on a 1-week cooldown, but you could make each of the six while you're leveling up. You don't get multiple skill points for those recipes.
Final Tally for materials used:
346 bolts of embersilk
69 volatile fire
3-34 volatile air
35-71 volatile water
If the multi skill recipes at 510 and 515 are fixed it would add 34 bolts of embersilk, 16 volatile fire, 8-12 volatile water and 12-16 volatile air to the list.
Also, Tailoring recipes were just added to the site. You can click any of the recipe links above to reach it :)