I'd say make a guide for a champion like Renekton or Ryze. both are fairly simple champions, but they're also champions that skill level difference can be seen in, (expecially ryze, for those who think you jsut roll your face on the keyboard to win with him, you could also go into extented combos and harass techniques as well as situational levelling and stuff.)
Personally I'd pick Ryze because theres actually quite a few mechanics about him that a lot of people don't realise. As for the extended combo, you can use q then immediately press R so you get the AOE effect of the first Q before it hits the enemy, in addition to taking 1 second off the cooldown of your Q. so the combo would be something like Q R Q W Q E Q, This particular combo will give you plenty of spellvamp in a trade, Like an Irelia's Bladesurge, only more powerful and the heal heals you for more too.
Like you, I am also Gold 4, and I have also been playing since late season 2 (lulu patch I think I joined?)
I know a few things so if you need any help, jsut gimmie a shout man, best of luck!