One of the most useful keys you can use in Photoshop is the Shift key. If you want to simply draw a straight line or keep a gradient level then holding down the shift is the way to go.

When used with Brushes, Pencil, Dodge and Burn, Eraser, Blur, Sharpen and Smudge holding down the shift key will enable you to draw in a perfectly straight line either vertical or horizontal.

In addition if you wanted to draw a straight line between two points then simply click on a start point, hold down shift and click on where you’d like your line to end.

The shift key does of course have many other functions but probably our most used one is keep the aspect ratio of a layer we’re transforming. Again it’s as simple as holding down shift whilst applying your transformation.

Here’s short video showing you exactly what I mean…… enjoy!