Well, in previous games, Letters would go by line (if you were in it to get gifts) But in New Leaf, it's much diffrent and i am still trying to figure it out, but what i have so far is that you should fill the entire letter, mostly with things like 'Please stay in (town name) or 'You are so cool' ect. I am not sure how it goes towards friendship levels yet but i will check that out. However, if you are in it to get gifts, you could simply write 'Please send fruit back!' then attatch a native fruit. (also, the animals wear clothes you send them through mail
once i wrote something really sad telling curt about my feelings then curt sent something like sending sympathy saying he'll be be by my side no matter what but i always attach a gift to the letter befor sending
I send stuff like "I really like your house" or "You're a really cool friend" and send them stuff I don't want like the stuff from balloons and fortune cookies. I also send them mail telling them to donate to my public works projects.
I Always try to write a lot of different things, so each letter is unique. lately, i've been writing them messages that say something about the type of animal they are. Like, fun facts about their species, or a couple of really worried letters to my frog who wanted me to catch a tadpole... he really should be more carefull with his children>_>
I usually write weird things pertaining to their name or species...Like asking Jeremiah if he likes frog legs and Tipper if she ever went cow tipping. I also included the lyrics to Jeremiah was a bullfrog to him once. When I am short on time though I just stick to generic friendly chatter.
Athryl's Adventures in Mop photostream:
When I played Wild World, I used to just write random things for the sake of sending letters to people, but now on this game, I wifi with people much more frequently, so I always try to write something interesting so that if my villagers move away to a friend's town, or I'd they show their letters to my friends whilst visiting, they'll be enjoyable to read. As a result of this, I don't write that many letters.
I once sent Jitters a pitfall seed, and gave him instructions on how to plant one, telling him to "walk over it. Something cool happens."
I really liked the feature in this game of being able to change how you sign your letters, and address them.
Currently in Termina:
Fauna, Skye, Grizzly, Amelia, Jitters, Agnes, Walker, Savannah and Sprinkle
Like, I send a letter to Bill (sporty personality) saying we should swim in the ocean, because even though he claims to work out, his light strolls around town are very ineffective as far as workouts go.
I basically do it for my own benefit and for those that visit me, for laughs. Not to actually make friends with anyone. XD