In order to maximise spiritbonding time, always try to use HQ gear and spiritbond potions to speed things along (You won't need to use spiritbond potions for grade 1 materia farming).

Grade 1 -

Leather Calot (LTW)
Hempen Kurta (WVR)
Hempen Halfgloves (WVR)
Merchant's Purse (LTW)
Hempen Breeches of Crafting (WVR)
Maple Clogs (CRP)

Create several sets of this gear and then use it just outside of any of the main city gates (Ul'Dah, Gridania and Limsa, except the White Wolf Gate in Gridania) as a high level DPS class and they spiritbond quite quickly, plus all the animal skins you get can be sold back to the NPC.

Grade 2 -

Mythril Choker (GSM)
Wolf Earrings (GSM)
Mythril Wristlets of Crafting (GSM)
Mythril Ring of Crafting x2 (GSM)

Equip onto a DPS class (you may want to also add a random element + grade 1 materia onto the choker as it is the highest at level 39 and will therefore bond a bit slower than the rest of the items - it's not necessary though) and farm in such places as Coerthas Central Highlands (Ornery Karakul), Eastern Thanalan (Gold Snurble) and I'm sure there's other places around. These will also have a chance of giving you grade 3 materia as well.

Grade 3 -

Electrum Choker (GSM)
Red Coral Earrings (GSM)
Electrum Wristlets of Crafting (GSM)
Electrum Ring of Crafting x2 (GSM)

Equip onto a DPS class (again, add random materia to the choker as it's a higher level than the rest - not necessary). These have a small chance to convert to grade 4 materia as well.

Use a DPS class in Mor Dhona, kill any mobs here, if you want to get crafting materials, you can specifically farm the Nix, Hipppogryph, Mudpuppy, Morbol. You can also farm the Wild Hog in Urth's Fount (South Shroud) and I'm sure that you can find other places for them as well. You may get away with farming in Coerthas West but I'm not sure if the items will actually bond and your remaining gear will need to be a high level in order to compensate for the loss of stats on your right side anyway.

Grade 4 -

This one should be obtainable from the following set at a 100% rate but since I haven't fully tested it yet, can't be verified. (I will confirm eventually though).

Ramie Turban of Crafting (WVR)
Ramie Doublet of Crafting (WVR)
Dhalmelskin Halfgloves of Crafting (LTW)
Rainbow Apron (WVR)
Ramie Skirt (WVR)
Dhalmelskin Shoes (LTW)
Holy Cedar Necklace (CRP)
Yeti Fang Earrings (GSM)
Holy Cedar Armillae (CRP)
Holy Cedar Ring x2 (CRP)

If that set doesn't give 100% drop rate for grade 4, it may well still be better overall as the materials will be a) easier to make when using your best gear and b) some of the items listed in the following gearset are crafts that are listed in the master book III (marked with a *) and the books can only be obtained through collecting blue scrips. However, it should have a better chance of dropping grade 5 crafting materia due to its higher item level (once they release grade 5 materia anyway).

You should make a set of this gear (listed below) when you can as it will be with you for a little while and can be considered the best gear since the job specific gear appears to be a massive grindfest currrently (someone put it at almost a year to obtain all materials for all 8 craft classes, and that's if you HQ each piece first time).

Chimerical Felt Turban of Crafting (WVR) *
Chimerical Felt Doublet of Crafting (WVR) *
Serpentskin Halfgloves of Crafting (LTW) *
Dragonskin Belt of Crafting (LTW) *
Chimerical Felt Skirt (WVR) *
Serpentskin Shoes (LTW) *
Hallowed Chestnut Necklace (CRP)
Dragon Fang Earrings (GSM)
Hallowed Chestnut Armillae (CRP)
Hallowed Chestnut Ring x2 (CRP)

(There are better accessories in the master III books now but this gearset will give you the best chance of making them HQ).

Grade 5 still seems to be unobtainable at this time (except by visiting mutamix), it may well be released in 3.1 and as stated earlier, red scrips block most of the job specific level 60 gear as well so I will update this when I can.

If you're top end and want to be getting into the highest level crafting sooner, farming for grade 3 and 4 are your best bets for now. Happy farming :)