Here is a list of methods that you can obtain Gold Leaves in MapleStory M!

MapleStory M Extract Equipment

Extracting equipment costs mesos but yields some gold leaves

Rank	Gold Leaves	Occult Cubes	Meso (Weapon)	Meso (Armor)
Normal	0-7	0-1	500	100
Rare	0-29	0-2	2000	2000
Epic	0-73	0-3	5000	300
Unique	0-147	0-4	10000	500

MapleStory M Dailies / Weeklies

Daily Missions

Daily/weekly tasks that can be done by daily basis.

Daily Tasks	Gold Leaves
Clear a Mini Dungeon 1 time	150
Clear a Elite Dungeon 1 time	150
Clear a Daily Dungeon 1 time	150
Expedition cleared 2 times	100

Dungeons

There is also dungeons that give you gold leaves that you can do daily.

Dungeon	Gold Leaves	Runs per day
Nett”s Pyramid (Normal)	0, 20, 50	4
Nett”s Pyramid (Hard)	0, 50, 100	4
Nett”s Pyramid (Chaos)	0, 80, 140	4
Zakum (Normal)	400	2
Zakum (Hard)	400?	2

Weekly Missions

Weekly Activity missions. You’ll be able to finish weekly activity mission by doing atleast 7 tasks on 6 days and 8 tasks on one day .

Mission Done	Gold Leaves
10	100
15	100
20	200
25	200
35	300
40	300
50	400

Scenarios

• Optimal scenario (every Chaos Nett’s runs yield 140, Hard Zakum x2, 45 Guild attendance), you would get your weapon from epic to legendary in approximately 65 days, not including achievements, extracts or Guide Missions.
• Common scenario (Chaos Nett’s yields 160 total, Normal Zakum x1) would be 144 days
• Worst scenario (Chaos Nett’s yields 0 total, Normal Zakum x1) would make that 218 days.

Source: 932uks Guide to Gold Leaves