1. Know your equipment so you will be able to shoot from darkness to daylight. I needed to shoot in Manual mode until daylight to achieve a proper exposure while keeping my ISO reasonably low. Always use natural ambient light. 
2. Have spare batteries since they will deplete more quickly in extreme cold or hot situations and always carry spare camera cards. 
3. Don't be afraid to ask questions so you can understand what is happening and what you should anticipate. Be friendly, respectful and non intrusive. Do not put yourself or the participants in danger.
Dawn PatrolColorful balloons pre dawn at the balloon festival.
Here are my images from the Albuquerque International Balloon Festival. Albuquerque geography in the high desert creates a special effect called the "box" where wind currents allow pilots to fly in a box-like pattern, sometimes landing right back where they started. The grounds open at 5 am where the Dawn Patrol balloonists are already starting preparations in the dark. They clear out the fuel lines with fire, then they spread out the balloon flat on the ground and use powerful fans to inflate. Then all these dawn patrol balloonists and their volunteers fire the balloons with the hot air lighting up the sky in brilliant colors.  They use powerful  fans on each side to blow cold air to start the inflation. Then finally switch to flaming hot air to lift the balloon and the passenger basket upright.

Then all these dawn patrol balloonists and their volunteers fire the balloons with the hot air lighting up the sky in brilliant colors.

20161004_BalloonFestival_063Balloon getting ready for pre dawn lift off at the International Balloon festival

With the start of the mass ascension at daybreak, hundreds of balloons launch in two waves, orchestrated by the "Zebras".

Mass Ascension StartingGetting ready for mass ascension of balloons in two phases.

Balloon ParadeColorful balloons during mass ascension.

The sky was filled with hundreds of colorful balloons.  And their chase cars needed to follow them for pick up when they landed.