There is a technique to cafetierre coffee, but you have to use a rougher grind than Lavazza Espresso, you can still get a good, strong cup of coffee from it, i just find it's a bit less consistent than a stove top (and isn't as strong).
The most common mistake is to use boiling water, which is a disaster, burns the coffee and makes it bitter. The water has to be at the right temperature, i can;t tell you what it is, it's a trial and error/instinct thing. Pour a small amount of water onto the coffee grounds, stir and let it steep for a while (10 seconds maybe). If you have good quality, fresh coffee that'll produce a nice thick creamy foam layer that you don't get from a stove-top. Then you pour the rest of the water in slowly and let it brew for about 4 minutes. I also find a lot of people are too stingy with the amount of coffee they put in, the packets say a spoonful per person or something, i go for 2 spoons per person. Once coffee is brewed you can always dilute it, but you can't make it stronger.