I'm curious about how to use concealer well.

As you can see in the photo, my skin has a lot of scars and blemishes.

I'm using concealer for the first time and I'm curious about how to achieve natural-looking coverage. I've heard that applying a thick layer to cover blemishes and dark circles can cause clumping and accentuate wrinkles, so I'd like to know if it's better to apply small amounts multiple times. I'd also like to know which tool—a brush, a puff, or my fingers—provides the best adherence. Please also recommend brands that offer good staying power and are suitable for dry skin.

I'm wondering if it's better to choose a color that is half a shade lighter than my skin tone, and if peach tones are effective for dark circles.

Please also give me tips on how to maintain it for a long time without it collapsing.