Like Paperboy mentioned, there are definitely alternatives to making TBT.
⇒ There is the
Museum Shop (General Discussion sub-section > Museum > Museum Shop) where you can sell your art if you have an artistic inclination.
⇒ The
TBT Marketplace (Town Hall sub-section > TBT Marketplace) is a place where you can buy/sell collectibles and all that jazz.
⇒ And the there is
Re-Tail (Animal Crossing: New Leaf sub-section > Re-Tail) where you can buy/sell any in-game items and/or services. For example:
⮩ You can sell furniture sets/(hybrid) flowers/bush starts/tree starts/etc. You name it, someone wants it!
⮩ OR if you, like some others, have a second town (or if you don't mind doing it in your own town) you can basically "sell" villagers. When a villager in your town wants to move, you'd post that you have a villager for sale and can request either in-game bells (or "IGB") or belltree bells ("TBT"). Then, when the villager is all packed up in boxes, you'd have the person who is buying them from you come and talk to them, asking them to move to their town. They'd send you TBT or drop off the IGB for you and ba-da-bing, ba-da-boom. YA DID IT.
All in all, there are lotsa ways to make TBT. The main takeaway is that, if you wanna make TBT, interact with the community here!