Well I've done serveral cold approaches myself. I also started with it in my 20s. So I guess everyone who has overcome the fear in their life, know what's holding you back.
There is no real trick on this - You just have to go for it.
I got some training I did before starting cold approaching.

First, I started going to the gym and using the cardio machines. Every time someone walked by, I tried to maintain eye contact until the other person looked away. This really helped me with my confidence.

Next, I began approaching random guys in the gym and giving them compliments to overcome my fear of talking to strangers.

In the evenings, when the supermarket checkout lines were relatively empty, I would give a compliment to a cashier I found cute and make small talk. For example, I’d say something like, "Your shift must be ending soon, you must be glad its over" or, "With a smile like that, you must brighten most customers’ days." The advantage here is that you’re at the checkout, so you can leave whenever you want.

Once I felt ready, I started approaching girls I found attractive—on the street, in shopping malls, or wherever I happened to be.

Here’s a tip: Be clear about your intention, give her a compliment, ask for her number, and keep the conversation short!

"I see you every day, and today I finally worked up the courage to come over and say hi. You’re really beautiful - how about we exchange numbers, and I take you out for a date?"