use a direct connection to your route/modem. make sure your the only 1 using it.
dont download while you play. get an isp that provides cable services over fiber rather than copper wire.
connect to local servers rather than half way round the world.
20-50 ping is playable more than 150 isnt. so check the ping to the server and make sure its under 100 at the most.
1- Get a better connection
2- Close all other application that leeches your data ( anti virus , automatic updates, streaming etc )
3- Get closer to the server
4- Use VPN if you thing all above 3 options are ok