Hands down, no questions asked, Great Buildings will effectively change and skew your city to the play style you desire (especially for GvG, but GE too). The biggest struggle when it comes to this though, is acquiring all the blueprints you need in order to plant a GB in your city. There are a few ways to go about this, with some methods being more effective than others. Depending on how badly you need BPs will determine what method, or combination of methods, you’ll want to employ to get them.

Aiding/Plundering
With the exception (currently) of Observatory 1, Temple of Relics 2, and Oracle of Delphi 3; you have the chance to earn a BP from any building that you aid/plunder. The BP will only be for a GB that is associated with the age of the building you have hit. For example, if you aid/plunder a house from the Early Middle Ages, you have a chance at getting a BP for Cathedral of Aachen or Hagia Sophia (because they are the EMA GBs). There’s no guarantee that this will succeed in giving you a BP though, even with a GB like Rain Forest Project to increase the odds, so it’s not the best method to rely on beyond Iron Age. Thankfully for players with young cities (aka young mates), you can typically be much more successful at getting BPs for Zeus and LOA simply by aiding your whole neighborhood. Odds seem to be in your favor at this time. The biggest benefit to this method though, is it doesn’t cost you a thing to aid (plundering might lose you some troops, or get you revenge attacked and plundered though if you don’t have good defenses).

General Swap Threads
If you already have a GB (preferably not Oracle of Delphi though), then you can play in the general swap threads your guild has set up to try and earn BPs. This is an extremely fickle mistress though as far as ways to earn BPs (or any rewards, really) goes, because even with decent swap thread etiquette, there is no guarantee that you will place on a GB. In fact, the odds are extremely against you in this case for two reasons:

  1. You can’t be certain that the GB you’re working to place in a reward spot on will be up in a swap thread when it’s convenient for you to follow it, thus putting more FPs on to help lock your spot.
  2. Since it’s a general swap, it’s anyone’s game at taking rewards who has ever taken a swap. This really isn’t considered sniping because a GB in the general swaps is fair game to a whole guild.

So essentially, unless a general swap thread puts you immediately into a position where you can lock a spot, it’s the worst choice of where you can spend your FPs to try and get BPs (and other rewards).

Dedicated Swaps
A dedicated swap is a great way to get BPs because this is a GB that a player is going to keep out of any other swap to let you get locked into place on. In addition, they will place FPs in a GB of yours that they want BPs for, meaning your GB also gets leveled at the same time. This is great in an instance where, for example, you have COA but not CDM, and you find a mate who has CDM but not COA, and you two can donate to each others GBs to get the BPs you need. It’s a win-win situation. This is the most efficient way to spend your FPs to get BPs when you already have a GB that can also be leveled, because it’s effectively doing two things at once while effectively guaranteeing 4 that you earn the best reward possible. This could be done with more than one person, but it’s easiest with just a pair of mates.

Dedicated FPs
If you are a young mate who doesn’t have a GB to use in a swap (or if you have other reasons to not want to do a dedicated swap/can’t find a partner, regardless of your city’s age), then at least dedicating your FPs (or a significant portion of them) to a GB of your choice that you’re hunting BPs for until you lock your position is a decent way to spend your FPs. This doesn’t have the added benefit of leveling your own GB at the same time, but it effectively does the same thing as a dedicated swap. You will probably want to contact the GB owner to see if they would keep it out of the general swaps (or to make sure they aren’t in a dedicated swap or group if there are already FPs on it from others) before you start in on this. If they’re really awesome, they’ll self-level some to help you place a bit more inexpensively (and faster). It’s in their best interest too, since their GB is getting leveled after all.

Leveling Groups
This particular option is for those who have a GB, and want to get the BPs to take it beyond level 10. These are groups that get together with the same GB, and decide on a fashion in which they will level each others GBs to earn the rewards. There are a lot of ways to set these up, but the main idea is that you’re all working together to get rewards and BPs for the same GB that you all want to really push. Remember, the first set of 9 BPs will take you to level 10 on all GBs. Beyond that, each subsequent level takes another full set of 9 BPs. It’s hard work! This is a good way for a dedicated group of mates to share the expense of earning these BPs, and to get their GBs up at the same time. The speed of them depends entirely on how much the group can afford as a whole, and other parameters that have to be discussed.

Blueprint Opportunities
Guilds generally have a thread set up where mates who have GBs that are close to leveling can post them if there are still rewards available. These GBs are open to the entire guild to place on, and as such if you want a spot on a specific GB you will want to call it in the thread (IE: On 3 for John Smith’s Zeus) before you start donating any FPs. This helps to ensure that two mates aren’t aiming for the same spot at the same time, and thus one loses out because the other was faster (and thus spends FPs needlessly). While this isn’t as effective necessarily as a dedicated swap or donation, it is a great way to earn BPs (and other rewards) if you’re on at the right time and have the FPs to spare. Just be aware that in this thread, it’s lock it or lose it (especially with high level GBs)! This means if you don’t immediately lock your spot, don’t expect it to still be there when you go back to try. GBs placed in this kind of thread are fair game to the whole guild after all. Also, as a note of etiquette here, it is considered extremely rude to level someones GB in this thread if they haven’t expressly said it is okay (or it’s not Zeus or ToR that have no rewards), because they might be aiming to double-dip (collect the reward when the timer is up, level it, and collect again immediately). So don’t be that person.

Sniping
Sniping is the practice of sliding into a GB you were either watching (most do this by placing 1 FP on it and then just checking their GB list regularly) or noticed, and taking a reward spot out from under others. You should never ever snipe your guild mates, but this method can be extremely effective when you’re cruising your Neighborhood or Friend’s List. It’s a lot easier to do this with a powered up Arc, but it’s still possible to do it without Arc at all, too. You just need to be extremely diligent. Of all the methods, this one requires the most math and the most time to pull off, and it’s not guaranteed that you’ll find any fruits for your labor. It feels really good when you do, though.

In essence, there are a lot of ways to get BPs (and other rewards that come with GBs, too), and they have varying degrees of effectiveness. Often, it’s best to apply more than one method to hunt down BPs, but again, depending on the urgency of acquiring them or the resources available to you (aka how many FPs you get in a day), you might only want or be able to employ a single method for now. That’s something to be determined by your individual needs though.

And of course, if you’re lucky, you might be able to turn those duplicate BPs into one that you’re missing. Typically though, the odds are really, really, REALLY against you on this, so it’s not advisable once you’ve planted the GB in the ground and want to take it beyond level 10.

Happy hunting!

Notes:
1: Observatory BPs can only be earned through placing in a reward slot on the GB itself, or by winning them in an event when they’re offered. You cannot earn these by aiding/plundering.
2: Temple of Relic BPs can only be earned through placing in a reward slot on the GB itself, or by winning them in the Guild Expedition if they’re a potential prize in a chest. You cannot earn these by aiding/plundering.
3: Oracle of Delphi BPs can only be earned through placing in a reward slot on the GB itself, or by getting them from the initial quests in Bronze Age in preparation to learn about GBs and how they work. You cannot earn these by aiding/plundering.
4: There is no guarantee, especially with high-level GBs, that someone from outside your guild won’t snipe you and steal your spot. However, this is typically unlikely on low-level GBs where there is no self-leveling.