Toe in is the easiest to do for a backyard mechanic.

On most cars, caster is not adjustable unless you want to do something like switch the control arms. Changing caster can give you a handling advantage, but it can also stress axles beyond their design parameters. On the Honda Challenge Prelude, Corey broke two high strength axles before he realised that the increased caster was just over stressing them.

When you make changes to an EP3 or DC5 by lowering the car, it's the toe in and thrust angle that are the most important to fix. It's possible that your regular garage will not be able to fix the thrust angle if it's wrong, which could necessitate paying for a "competition alignment" the first time after lowering a McPherson car.

Camber adjustments can be an important part of making a car handle better; however, camber is usually not what's wearing out your tyres. It's usually a bad toe in alignment or total thrust angle that is causing your car to handle strange and the tyres to wear.

Camber up to about 3 degrees negative is not really going to wear tyres. It's dumb to have 3 degrees camber on a street car, though, because you're reducing the tyre's effectiveness in a straight line.