I am not sure these are tips so much as observations from years of making paella.
The goal is two-fold; flavor and socarrat. Socarrat is the crust on the bottom of the rice where it was roasted against the pan. Put differently, the two biggest causes of mediocre (or worse) paella is bland flavor and rice without the proper crust.
Combatting blandness is not as easy at is sounds. You would think that it would be hard to get bland flavors with good chorizzo or languica and a decent sofrito but it happens to the best of us. Using home made chicken stock helps immensely. So does high quality saffron. I thought I got a good deal on saffron recently while vacationing in Israel but I got bland flavorless stuff that barely resembles saffron.
Alright-just my two sense and not worth much more; cooking paella over a fire may be romantic but it makes getting the socarrat much more difficult. Fires mean intense and uneven heat. Granted, this is a BBQ site and you naturally want to put that paella pan over a Weber and I do the same. That said, the home pro's use a multi-ring gas burner made just for cooking paella. This way you can control the heat level, insure that the heat is distributed evenly across the pan, and monitor the rice until the formation of socarrat is confirmed. Given that you are are likely going to use the Weber, 90% of the time by the time I've sauteed my sofrito, sauteed my chicken thighs and sausage, and added the rice and ladled my stock and added all ingredients for the final stage of the cook, my charcoal has lost it's intense heat and my fire is not hot enough to get the socarrat. Consider getting a second chimney of fresh briquets going and undertaking the effort to lift and remove the pan and unload the fresh briquets. All the books and web recipes call for covering with foil towards the end-i suggest not doing so. You need access to the pan to periodically dap a long handled spatula deep to the bottom and check for the socarrat formation.
Good luck and may your paellas be more consistently good than my own!
