Now, this thread only regards to people who have high lag/ping, so if you don't have those then you do not need to look here.
Now, I have been playing CS:S and CS:GO for a bit now and find that my Ping/Lag is over the top, so I have found a few solutions that work for me.
1. Closing everything else besides the game you are playing (You probably already know this)
2. Minimizing the game and un-minimizing seems to work.
3. Get rid of any junk on your computer so you can free up memory.
4. Try not to run servers on that Computer
5. If you normally have a slow internet connection, try and get a faster one.
6. Turning graphics down will help.
Hope this helps.
My first thread on this great forum.
Thanks for reading Guys