Don't just copy-paste the tweaks and settings that others have provided but instead take it as a reference as to how much your card might be able to go.

Use overdriveNtool and use it to downclock core with corevoltage as much as you can without any effect on hashrate.
Then try to increase the memory clock until you hit any memory errors, don't try to make changes into memory voltage as they are hard coded.

After all of this is done and you have a stable config for this, try the default values of Memtweaker and apply it just before you are starting the mining application.
All of this will provide you with much better hashrate and low power consumption.

Note: Check if the memory vendor of your card is Samsung as they OC the best in memory. (GPU-z)