You have to learn how to read and predict weather conditions, by looking at washing on lines, smoke, the little cloud over there that's been building for the last half-hour which before long will be a great big thunder storm etc. It's seat-of-the-pants stuff, like in the days of early aviation.
Going up or down is no problem. You can control that to within two or three centimetres (using the heat and the vent at the top), and speed is also quite easy to control - the lower you are, the slower you travel because the wind blowing over the earth's surface is slowed by obstructions, trees and houses.
Steering is more tricky. You can't say, "I'm going to fly to Wales today", for example. Where you end up depends on the prevailing wind. It might look like a nice sunny day, but always contact your local Met office for a forecast before you fly. If there's a chance of thunderstorms, don't even think about going up. There's a danger of the balloon getting damaged or even worse, being sucked up by the thermal activity to such a height that you'd need oxygen. When landing, choose a field that doesn't contain animals or an uncut crop, so you're not doing any damage.
Landowners and farmers rarely mind, but during the Bristol Balloon Fiesta, when some end up with 20 or 30 balloons on their property, it's obviously an inconvenience, so it's become traditional for each balloonist to offer them a bottle of whisky as a thank-you.
Phil Dunnington will be in one of the 150 hot air balloons taking off each day at 6am and 6pm in the Bristol Balloon Fiesta, 5 to 8 August. Call 09068 252262 for details