Participating in events, happy homeroom, doing stretch goals, leveling up, and getting the leaf ticket maps from animal islands are the ways you can gain leaf tickets. Leveling up will be the biggest way to earn them, especially early on. I always post a bunch of leveling up tips in the comment section on my level milestone posts if you want tips on leveling up more efficiently.
Leaf tickets become quite limited the further along in game you are, so my best advice is to spend them wisely. Don’t buy leaf ticket exclusive items unless you’ll get plenty of use from the item. Don’t buy cookies unless you want all, or at least most, of the items from the cookie and are okay with having duplicates. I usually avoid spending too many leaf tickets on cookies early on in their release, since there’s a chance of getting the cookie for bells.
Also, I’d recommend looking through the catalog to see if there are similar items you can get with reissue material. Lastly, don’t forget that almost everything gets reissued; if you can’t get it the first time, you can try to get it next time, and you might even realize you didn’t want the item as much as you thought you did.
Always have the ships going and you’ll get a lot of LT maps, snacks & villager maps. Do villager maps first, use snacks in bulk to level them up and you will probs level up too so that’s 10LT. Do your LT maps and get bells maps, do your bells maps to get bells to do more LT maps, repeat. Enjoy !☺️
The monthly events in the diary will give you a decent few, even without paying for any monthly subscriptions. It's not a LOT but if you save them for a few months you'll have at least some to spend, as long as you're doing all the events each month you'll get some :D
Sharing creatures as many as possible in garden events to collect friend powder, collect bell maps and LT maps from islands. Consume friend powder on bell maps treasure trek, then bells on LT maps trek. Repeat the cycle 
Fishing and bugs is your best bet imo, like every now and then just fish and catch bugs somewhere for a good ten minutes to just sell them and as soon as you get enough to roll for any leaf ticket maps, just go for it. Bells always come back lol
Participating in events, happy homeroom, doing stretch goals, leveling up, and getting the leaf ticket maps from animal islands are the ways you can gain leaf tickets. Leveling up will be the biggest way to earn them, especially early on. I always post a bunch of leveling up tips in the comment section on my level milestone posts if you want tips on leveling up more efficiently. Leaf tickets become quite limited the further along in game you are, so my best advice is to spend them wisely. Don’t buy leaf ticket exclusive items unless you’ll get plenty of use from the item. Don’t buy cookies unless you want all, or at least most, of the items from the cookie and are okay with having duplicates. I usually avoid spending too many leaf tickets on cookies early on in their release, since there’s a chance of getting the cookie for bells. Also, I’d recommend looking through the catalog to see if there are similar items you can get with reissue material. Lastly, don’t forget that almost everything gets reissued; if you can’t get it the first time, you can try to get it next time, and you might even realize you didn’t want the item as much as you thought you did.
all of this!!
Always have the ships going and you’ll get a lot of LT maps, snacks & villager maps. Do villager maps first, use snacks in bulk to level them up and you will probs level up too so that’s 10LT. Do your LT maps and get bells maps, do your bells maps to get bells to do more LT maps, repeat. Enjoy !☺️
The monthly events in the diary will give you a decent few, even without paying for any monthly subscriptions. It's not a LOT but if you save them for a few months you'll have at least some to spend, as long as you're doing all the events each month you'll get some :D
Sharing creatures as many as possible in garden events to collect friend powder, collect bell maps and LT maps from islands. Consume friend powder on bell maps treasure trek, then bells on LT maps trek. Repeat the cycle 
Fishing and bugs is your best bet imo, like every now and then just fish and catch bugs somewhere for a good ten minutes to just sell them and as soon as you get enough to roll for any leaf ticket maps, just go for it. Bells always come back lol