How do you say welcome officially?

Greetings, esteemed listener. I am curious to know, in the realm of formal etiquette, what is the most appropriate way to convey a warm and sincere welcome? Is it through a grandiose greeting laden with formalities, or a more succinct yet heartfelt expression? How does one strike the perfect balance between demonstrating respect and fostering a sense of warmth and camaraderie? I am eager to hear your thoughts on this matter.