How to detect for player with custom head

Solution 1:

Create scoreboard wSkull: scoreboard objectives add wSkull dummy

[1]Repeating command block: scoreboard players set @a wSkull 1 {Inventory:[{Slot:103b,id:"minecraft:skull",tag:{display:{Name:"Leafy Headdress",Lore:["[Rare] [Quest Item]","Some irritating thorns poke out of it."]}}}]}

[2]Repeating command block: execute @a[score_wSkull_min=1] ~ ~ ~ [command you want to happen when the custom head was worn]

At [2]Repeating command block, you can do multiple of these if you want alot of things to happen whoever wears your head.

Slot:103b locates where the helmet should be put when you want to wear it inside your inventory.