NsGpuCNMiner.exe -xpool stratum+ssl://cryptonight.eu.nicehash.com:33355 -xwal btc-addr.rig1 -xpsw x -h 928 -dmem 1 -cclock 1167 -cvddc 875 -mclock 2000 -mvddc 875

btc-addr - is yours nicehash btc address
rig - is your rig name ( if you use it )
This is setup for 4GB vram card , if you have 8GB you can change -h 928 to -h 1800-1900 , just test it to find thah best fits to you , "-cclock 1167 -cvddc 875 -mclock 2000 -mvddc 875" - this is core and memory speed and voltage , edit it to fits for you or just delete it if you use other program to overclock/undervolt.