Using tactics means to use all the techniques you have been taught, but in relation to your ability. For example, if you are slow on your feet, avoid the balestra . If you don't have the reach and the speed, be careful with your lunge. If your disengage is a big circle, train yourself to make it smailer. Surely you can think of other bad habits you have developed over the years.
Many fencers argue that luck plays a big part in all bouts.
The lucky touch often can and does take place, but it may simply mean that one fencer continued to think and keep his wits while the other gave in to impatience or frustration. If your opponent dances and hops, you can't be sure when the real attack will come. If you dance too, you may be compounding your problem. Here you have a basis for formulating your own strategy. Evaluate, and refrain from attacking blindly.