My moveset is simple (Mostly Special moves bare in mind), BUT not easy, So long as your Dragonite has no high or low stats, with the natures: "Hardy, Docile, Bashful, Quirky or Serious", then teach it the special attacks! Or If your Dragonite has a "Modest" nature then it is an added bonus for all attacks to be special!!
Anyway, my moveset i've teached my Dragonite at level 100 with the nature "Serious" is:
Surf (Against Rock, Fire, Ground)
Thunderbold (Against Water, Flying)
- Fire Blast (Against Grass, Ice, Bug, Steel)
- Outrage (Against Dragon and "Other Pokemon")
Bare in mind that if you use the move Surf and then Thunderbolt on a "Normal" pokemon, the effects can be devistating! Just imagine, if you got wet and then being electricuted; OUCH!!
But always use the move "Outrage" as a last resort! Do NOT give Dragonite Hyper Beam or Dragon Pulse! Unless it has a high Special Attack Stat!
Also, give Dragonite Yache Berry against Ice type attacks!! It can weaken the Ice moves!
And last but not least; Give it (If possible) Max PP on all moves as this will highten the amount of moves your Dragonite can use!