How to Get Jump Boost Boots In Minecraft

As Antoine and MBraedley stated in the comments, you will need these more or less complicated commands to make jump boost boots work without a mod.

First of all, we'll need to determine if the player is wearing some special boots and store this in a scoreboard objective. To create the objective, run

/scoreboard objectives add jumpBoots dummy

once. Now, create a 20Hz. clock (fill clock or use repeat/chain command blocks in 1.9) and put the following two commands

/scoreboard players set @a[score_jumpBoots_min=1] jumpBoots 0
/scoreboard players set @a jumpBoots 1 {Inventory:[{id:minecraft:diamond_boots,Slot:100b,tag:{display:{Name:"Jump Boots"}}}]}

This will set the score to 1 for every player wearing Diamond Boots (i.e. they are in slot #100) named "Jump Boots", and 0 for everyone else. You can modify the data tag of the boots to suit your needs, e.g. change it to leather boots or change the name.

On the same clock, you can then put

/effect @a[score_jumpBoots_min=1] minecraft:jump_boost 1 <amplifier> true 

Which will give the wearer of the boots 1 second of Jump Boost every tick. Replace <amplifier> with the level of jump boost you want to give minus 1, e.g. 2 for Jump Boost III. The true at the end hides the swirly particle effects, you can remove it if you want.

If you would like to get a jump boost in vanilla (normal/without mods) minecraft, I suggest you make a beacon (if you are in creative) and turn it on then right click and select jump boost, and then go into survival and walk through it, tada! For the parkour, you could start with the players walking through a beacon, and then beginning the parkour, also make sure that you have a lot of gems surrounding it so the effect lasts longer.

(my apologies if this doesn't help)

I have had to make jump boots before too, but the only way to do so that I have found is to put this super long command into a command block and add a button. It should give you them instantly. You can just copy and paste it into the command block.

give @p golden_boots 1 0 {display:{Name:"Jumping Boots",Lore:["gives you flying and jump boost and speed"]},AttributeModifiers:[{AttributeName:"generic.maxHealth",Name:"generic.maxHealth",Amount:5,Operation:0,UUIDMost:80901,UUIDLeast:98444},{AttributeName:"generic.followRange",Name:"generic.followRange",Amount:32,Operation:0,UUIDMost:13009,UUIDLeast:153291},{AttributeName:"generic.knockbackResistance",Name:"generic.knockbackResistance",Amount:20,Operation:0,UUIDMost:83502,UUIDLeast:718503},{AttributeName:"generic.movementSpeed",Name:"generic.movementSpeed",Amount:10,Operation:0,UUIDMost:19242,UUIDLeast:97406},{AttributeName:"generic.attackDamage",Name:"generic.attackDamage",Amount:5,Operation:0,UUIDMost:21041,UUIDLeast:883059}],ench:[{id:0,lvl:5},{id:2,lvl:6},{id:5,lvl:5},{id:6,lvl:1},{id:7,lvl:4},{id:8,lvl:3},{id:16,lvl:10},{id:19,lvl:10},{id:32,lvl:1000},{id:34,lvl:100}],HideFlags:5,Unbreakable:1}