You need to play as you normally would against all other players, but then shoot earlier, jump earlier when he is in the vicinity. But in a high paced game, you know you can't play two different ways.
The idea behind unlagged is that you don't have to play in two different ways, just shoot directly at him and regardless of his or your lag you will hit. In ordinary play you will need to look at your own ping and then calculate how much in front of the enemy you need to hit.
Unlagging a server is just trying to make it a bit more fair, so low pings are not that superior anymore (they still have the advantage though). With a limited number of players you cannot expect everyone to be able to connect to a server with a low ping.
In a time where every game demands broadband it might be hard to accept that dial ups should be allowed to play along.
The only way to solve the problem is to get people spread out to more servers, so they ping connect to low ping servers.
For spectators it could be nice to do delayed spectator, so that you can see what the client sees.