If you're trying to weld a contunuous bead around a piece like an exhaust pipe (in which strength isn't imperative), I find that it's easierst to hold the torch in the same direction as the exhaust pipe.
If welding for strength in something like a driveshaft, most definitely hold the torch so...
Welding two pipes or tubes together end to end is often easiest when you hold the torch parallel to them.
A trick I sometimes use to half-assedly preheat thicker metal is to add an extra tack about where you're going to start welding. If you wait a moment before starting to fully weld you not...