Now that I've had some personal experience with speeding through reincs, I can finally write a proper guide on the subject.
First of all, I will say that preparation beforehand is essential
. Taking time to set yourself up is very important in the long run.
On that note, now that I've tested it I cannot recommend Daveness' reinc guide
highly enough. In short, he recommends you have 4 full sets of speed up gear: 1 for your character, and 3 for 3 of your perm SS. That's 4 sets of speed items for each gear slot--hand, body, companion--which can be acquired from Adventures (Fealty banners in V4 L120 Adventures) or peerless crafts from the buildings (i.e. Cavalry Commander, Mastercrafted Cuirass).
Doing so will make your net completion speed close to 50% (including the level 30 speed-up talent, which accounts for 24%; between your SS and char gear, you need to make up the other 26%). This is important because it also cuts down the number of Bread you need by 50%. Typically, you would need 300 Bread to speed through a reincarnation, but with 50% completion speed that number is easily cut down to ~150. Not only does this mean that you can do twice the number of reincs with the same amount of Bread, but it also means that you'll be saving yourself 150 hours of baking time every single life (not to mention many, many mouse clicks). So definitely make it your goal to get your aggregate completion speed of quests to ~50% or more.
The maximum completion speed you can get for any one action is 70%, so the Premium Sand Steed Talent in the Martell tree, which provides 3% faster completion speed per rank, can be used to get the max speed of 70% quest speed. Just keep in mind that you may not need to waste the reincs through Martell if you can get enough speed seals on your items/SS (detailed in Daveness' guide), so keep track of how close your total completion speed is.
Now on to the actual reincarnating!
1) Prioritize getting to level 30, but don't spend ANY talent points until level 30
. The Adventure Party talent is the only exception. You want the 3 speed-up talents for your main stat as soon as you can, and so save up your talent points for them beforehand.
2) Sell every piece of gear you get
. You're not going to be spending time in this life, so the silver is going to be far more valuable to you than the item. If you set yourself up properly beforehand with Daveness' guide, your char/SS will have gear with 20-30 on a stat anyway so it's not as if you need the items anyway; you'll have much better gear already.
3) Acquire enough cheap SS to complete quests in all volumes simultaneously
. Already having extra perm SS will help if you have the Gold to spare. Besides the 3 you have for V1, you'll need 9 more for quests in other volumes. If you have to prioritize, just go in order: V2 first, then V3, V4, VF, and VU. This will give you extra silver, resources, character XP, and alignment options you'll need to claim the Valyrian Steel Dagger by the end of V1.
4) Acquire as many additional cheap SS as you have the Command Points for
. Send them out on Adventures for extra silver and resources. Personally, I like running the unique Cycle adventures--they take about an hour to complete with the 50% speed bonus, but for their difficulty level (which scales to your char level) they give a high amount of silver.
5) Buy cheap building upgrades whenever you can afford them
. Prioritize ones for your main stat, but also ones that aren't for much the same reason as 2) above: with proper gear, between your char and SS gear your functional strength will be 160-200 right off the bat, which is more than enough for most V1 quests. Upgrading buildings gives you character experience (not to mention Power) and so you will level up very quickly by purchasing the cheap upgrades.
6) Know which quests to speed up
. This is a trickier one. Sometimes, you'll find that you have 4 quests in the Quest Book ticked off out of 5, but for the last one you need to advance chapters, you won't have a quest active by that name. This is because there are often questlines leading up to the quests in the Book that aren't named, and so it can be difficult to find out which ones you need to speed up in order to advance. Other times there are quests you'll have active that you'll have plenty of time to complete (i.e. they appear in Chapter 7 but you don't need to finish them until the Epilogue; thus you don't want to waste speed-ups on them. Consult this post
for a complete list of questlines in Volume 1, and look for the quest you need to complete in order to find out which questlines you need to speed up.