1. Set the power limit to desired level
2. Increase core clock gradually until it's no longer stable then back it down a little bit
3. Increase memory clock gradually until it's no longer stable (or until your hashrate levels off) then back it down a little bit
BOOM done
You may have to do this for each algorithm
First of all thank you for your comment
So that's it? i saw people go upside down like -20 on memory clock so they can get more hash power !!
I am using Nicehash which is mining on three different algorithms automatically "Equihash\Lbry\Lyra2REv2" what should i do in this case?
You can oc that card to +60/80 without really doing anything. You can't really damage it as you aren't playing with voltage. As long as your psu cables can handle the increase in power when you adjust the power limit to max (117%), the worst that will happen is a driver crash or your PC locks up.