I often see drivers swerving out before making a turn. It may be a U-turn or a simple turn into a side lane - they always swerve out first. Is this the right way of doing things?
No, it is not, unless you are driving a trailer. A car's steering system allows you to make a turn safely without having to swerve out first.
This is true even if you are driving old Alfa Romeos, which have notoriously wide turning circles.
The way to do it would be not to steer immediately when you come to a kerb, but move slightly ahead before turning the wheel. This way, you avoid cutting into an oncoming lane too.
It is the same for a U-turn. Move slightly ahead before turning, so you can swing back in before meeting the kerb on the other side. Legal U-turns are designed to allow you to turn effortlessly - unless you are driving a trailer, of course.
Swerving out before making a turn is irritating to motorists behind you. Worse, you could collide with a vehicle in the next lane.