Strong linear perspective in photography is usually achieved by using wide-angle lenses—the wider the angle of view, the better the effect. However, perspective is not actually changed by zooming out, using a different lens, or adding wide-angle converters. Linear perspective can only be changed by viewpoint.
The perspective simply looks like it has altered because you have increased the angle of lens coverage. Because areas of the foreground that are much closer come into shot, the parallel lines appear to converge more sharply.
The perfect subjects for this approach are ones that have strong parallel lines—such as a road, or train tracks. Getting down low will ensure that the foreground is as close as possible—helping to exaggerate the effect of the wide lens.
Diminishing size is essentially a by-product of linear perspective. However, subjects of similar size will appear smaller the farther away they are, even if there are no converging lines. This illusion works best when the subjects look as identical to each other as possible. Like linear perspective, it can also be exaggerated using wide-angle lenses, and by being as close as possible to the nearest object.
Composing an image so that distant objects are partially obscured by ones that are closer can be used, together with other perspective tricks, in order to increase the feeling of depth. At its more extreme, you can set up a composition
so that foreground elements—such as branches of a tree—cut through the main subject in the distance. The distraction this may cause can be controlled by ensuring that the foreground is out of focus