From what I’ve seen, there’s two ways to ‘play’ a mesmer in PvP, when you’re 1v1’ing.
The first is if you’re playing a shatter-spamming build, where you can generate two full sets of illusions very quickly, and create a rather huge spike. This, combined with a Time Warp can win against almost anything in my experience. You can also use a more phantasm-focused build to deal a fairly steady stream of damage, which can be hard to overcome for most classes if they don’t bother to take out the illusions. However, it is not terribly difficult to find the real mesmer when doing either of these, as you either have few illusions up, or the phantasms which don’t look the same as you.
The second way is to play as if you were a clone: move little, don’t dodge unless you absolutely have to, and only use a non-autoattack skill when you are able to quickly generate more clones. This can be tricky to get the hang of, but by timing things right, it can be very difficult to find the real player. Since most clone-generating skills will displace you in some manner – Phase Retreat, Mirror Images, Decoy, Deceptive Evasion, etc – by alternating these skills along with invisibility, and the added damage from Sharper Images (since clones themselves output little), you can fool a fair number of people.
I personally use both, the shatter-spamming spike when on land, and the clone method when underwater, since I find the spear attack subpar for 1v1, compared to the trident attacks. Trident clones are also very awesome, because 3 Time Warped clones + you autoattacking can keep a large number of confusion stacks up on someone, and they will often very nearly kill themselves as they unload their attacks.
