Hi Luca: I would suggest several things:
1: Experience. The more tournaments you manage, the better, you're definitely on the right track
2: Variety. If it's popular at all in Italy, try managing games other than Holdem. Try stud, Omaha, high / low, and mixed games... If it's not popular yet, then introduce them. Also gain experience with all stakes: limit, no-limit, and pot limit.
3: Customer satisfaction. Ask your customers for feedback, what they would like to see improved...
4: Experiment with blind structures, awards, re-buys / add-ons, and (especially) payout ratios. The payout ratio is a major key to customer satisfaction IMO. The best overall structure will provide maximum payout ratio that is consistent with keeping the customer coming back, providing steady income for the house.
Here's a very short way to look at it: manage the event the way you would like to have it managed if you were playing in the tournament !
Looking forward to your posts!