Now I'm not gold+, but I do have quite a bit of experience jungling, so you can take my comments with a grain of salt. Also I apologize for the text-wally format of this post ahead of time.
First I'm going to discuss Nocturne. In the right hands he can be very effective, but Nocturne has the problem of he's got really good ganks when his ultimate is up, but when it's down he's not very threatening. His only gap closer (beyond his ultimate) is his attack speed steroid, which is also very important for chasing and escaping at the same time. He has a spell shield and a tether that turns into a fear. All in all his kit isn't really all too strong compared to a lot of the other junglers, but if you like him, don't let me stop you from playing him. I'd frankly suggest trying out J4, Vi, Elise, they each boast solid damage paired with CC and some relative tankiness. If you're really into the assassin style junglers, try out Kha'zix, same style of clear with a slight touch of sustain from his spikes, massive assassination potential at all phases of the game, even if behind.
Now a little thing about the jungle itself, in this season it's extremely important to be clearing your jungle, if you don't clear camps efficiently you fall behind very easily. I started jungling before we had actual timers in the game, now with the timers if someone spots your buff clear, or steals it without your knowledge, it's super easy for them to continue to do so. So that being said it's also extremely important to be hitting your blue and red camps when or shortly after they're up. I had a game recently where I countered the enemy's jungle extremely hard, because he focused on ganking way more than clearing his own jungle so his buffs were up for minutes after they spawned. After the 10 minute mark he didn't have buffs for 20 minutes which is the best way to completely shut down a jungler, not to mention that every time I countered the buff I left with at least one or both of the other camps on that side plus the scuttle in the river. So if you see their jungler ganking bot lane, look to see if he has buffs. The first camp they cleared should spawn somewhere between 7:15 and 7:40 depending on their clear speed assuming of course that they started at a different camp such as Gromp or Krugs, which most junglers do. I often like to start bot lane regardless of what side as I play junglers that can make use of either Krug or Gromp buff. So don't do that with Fiddlesticks. Finally for specifically jungle camp related stuff, don't overvalue dragon. The first and final buffs are the ones that impact the game most, the third isn't bad, but 2 and 4 aren't as useful. It's easy to throw an advantage because you overfocused taking dragons when you could have been getting towers. The priority is still Base Turrets > Baron > turrets outside the base > Dragon > Kills. If you can get a turret, let dragon sit it'll be safer after you take the turret.
Finally counter warding. I like to try and get entrances warded up when possible, the scuttle crab is not only a free ward with a speed bump, but it's also worth something like 80 gold from a camp that doesn't fight back. Seeing where the jungler goes in the river prevents you from being counter jungled, creates the opportunity for you to counter jungle, Great safety from getting ganked, or your laners getting ganked. It's everyone's job to ward, even though most people don't for whatever reason, don't be one of those people. I got my mid laner a very early start to snowballing from a double kill that only happened from a successful gank, then a sudden roam into the river because we spotted the enemy jungler and picked him up as well. so the 75 gold for a stealth ward gave up something like 450 gold to my laner and myself, which translates to a 600% return on investment. It's worth passing up a long sword believe me. So overall control the river as best you can, the enemy jungler is going to be very wary of ganking through river if you jump in and kill him a couple times when he tries it.