I use MSI Afterburner to tweak (although I'm using Asus Strix GPU), I learned from the forum members here too.
I tweaked to increase GPU memory frequency, incremental of 100MHz each time, click apply and let it stable for at least 10minutes, you can see the hashrate goes up real time, if PC is stable, I repeat the same step, 100MHz incremental until your PC hit instability, marked that unstable frequency and dial back.
After achieving stable memory frequency, you can play around with GPU power level dial also, that should help to lower your electricity bill abit, and enjoy lower temperature.
What are the values that are stable for you?
I'm living in a tropical country, hence my room temperature is ~29'C (~84'F). If you are in cold country, maybe can push the limit further,
In MSI Afterburner, I'm having this setting stable for 1day+ already for my GTX 1070:
Memory Clock (MHz) = +540
Core Clock (MHz) = +0
Power Limit (%) = 68%
Fan Speed Auto (sometimes I set to 60)
With above setting, I'm getting ~30MH/s, GPU temp = 55'C
Have you tried to underclock your core clock? I run my GTX 1080 TI with -400 MHz core clock and there is no difference in hash speed but temps are almost five degrees lower.
Don't use your 1080ti on eth, you are wasting time and power!
eth is for 1070/1060s only on the nvidia side
Seriously is there a good reason why I shouldn't mine with the GTX 1080 Ti. I'm not using it when I'm at work or sleeping and the electricity is basically free in Finland.