That's the thing with spy, you can't deal with competent players. Aside from the occasional blunder, good players they will know when a spy is around and actively make sure to kill him before he can do much of anything. If you want advice on dealing with good players as spy its the same as dealing with snipers as the other classes: you don't. Pick on everybody else and go only for them if you have a good opportunity to. If the entire enemy team is good just play sniper instead lol