Here are my top 10 lessons I learned the hard way about preventing acne scars. YMMV.

1. Dont pick at your blackheads too much. When I was a teenager, I spent countless hours in front of the mirror squeezing out blackheads with my fingers and a hairpin. Although squeezing the blackheads never directly scarred my skin, it did cause more acne to form. And the more acne you get, the more scars will follow, trust me. Its ok to extract the large blackheads, but its not necessary to extract every single little blackhead on your face. I have many more acne scars on the right side of my face than the left side. This is because I spent much more time picking blackheads from the right side (due to my right-handedness and also because the light bulb in the bathroom better lit the right side of my face).
2. Start Retin-A (Tretinoin) as soon as possible and give it time to work. I started tretinoin too late and gave up on it too soon. I started it only after I had already developed acne scars. The tretinoin made my skin red and dry which, in turn, made the scars looks worse. Because I was self-conscious of looking worse, I quit the tretinoin only after two weeks of use. This was a mistake. I should have asked the doctor for a weaker concentration of tretinoin, which might not have irritated my skin so much. Moreover, it takes several months for tretinoin to work, so I should have stuck with it longer. I will never know how much damage I could have prevented had I been more patient. Tretinoin not only helps to prevent acne but it also helps to build collagen, repair scars, fight aging, and prevent skin cancersomething I never knew when I was young. I currently take 0.01% Retin-A gel and am loving it.
3. Take an oral antibiotic (e.g., tetracycline) if necessary. Although this medication has its side effects (e.g, dry mouth and sun sensitivity), these temporary side effects are much better than permanent scars. I wish I had taken tetracycline during the worse years of my adolescent acne, which was between 14 and 16 years of age. Tetracycline doesnt cure acne but it does greatly reduce its severity.
4. Take Omega-3 supplements. I never ate seafood growing up, and I didnt start taking omega-3 supplements until my late twenties. Within a month of starting fish and flax oil supplements (dietary, not topical), my skin improved at least 50%. I wish I had started when I was a teenager. Youll need to experiment with the dosage. Taking too much might make your skin greasy, and taking too little wont be of any help either. Omega-3 was a game changer for me.
5. Control your blood sugar and insulin levels. Always eating too many calories keeps your blood insulin and glucose levels chronically high. This causes inflammation and makes your acne worse (as well as leads to type 2 diabetes). It took me 30 years to learn how to control my insulin. Firstly, you want to do frequent prolonged fasts. Every few months I go on a week-long vegetable soup fast. I also do a water fast one day each week. As soon as I started this fasting routine, my skin improved greatly. Secondly, you want to get regular intense cardiovascular exercise. Walking is not good enough. You need to get your heart pumping hard. I jog for 30 minutes three time a week. This helps burn off any excess stored glycogen and stabilizes insulin. And thirdly, keep your weight and your waist size normal.
6. Dont over dry your skin. When I was a teenager, I used to put globs of benzoyl peroxide on my pimples and leave them occluded all day. My reason for doing this was to kill the acne vulgaris bacteria, which made sense to me at the time. Unfortunately, this only made my skin worse. Instead of killing the bacteria, the benzoyl peroxide dried out my skin, slowed the healing process, and trapped the infection inside for too long. I believe this practice caused unnecessary scaring. Instead of benzoyl peroxide, what I do now is put a dollop of lotion on the pimple several times a day so as to moisturize it to death. Within a few days the pimple either slowly shrinks or forms a white head from which I can then safely extract the infection. Benzoyl peroxide is good for zits and body acne but not good for cystic acne (for me at least) which I had growing up. Cystic acne is too deep for the benzoyl peroxide to vanquish. So, its better to help the pimple purge itself using moisture rather than with a desiccant. The longer the infection remains under the skin, the more likely the skin will scar. I also sleep with a cool mist humidifier above my head to keep my skin from drying out at night since I live in a dry climate.
7. Find the cleanser that works best for you. Im always experimenting with new cleaners and lotions. Just because one cleanser works for one person doesnt mean it will work for you. Start by washing one side of your face with a trial cleanser. Do this until you can judge whether it made matters better or worse (days to weeks). Then repeat this trial-and-error exercise with other cleanser brands until you find the best one for you. For example, when my old shaving cream brand was discontinued, I had to switch to another, which made me break out badly along my jaw and neck. So, I had to keep trying new brands until I found one that worked. And just because the label says noncomedogenic doesnt mean it wont make you break out.
8. Exfoliate daily. Dead skin build-up leads to blackheads and acne. What works for me is to scratch my face with my finger nails in the shower while washing my face. Then after my skin is dry, I vigorously scrub my face with a damp wash cloth. I dont use chemical exfoliants or brushes of any kind because they irritate my skin. Just get that dead skin off your face as gently as you can.
9. Extract pimples carefully. Squeezing pimples that are not ready for extractionas well as waiting too long to extractwill increase the chances of scaring. When the pimple forms a white head or comedone of a sufficient size, either scratch the surface or poke the pore with a needle (I prefer safety pins because they are sharper than sewing needles). If you poke with a needle, insert it in the direction and angle that the hair grows to open up a drainage channel without damaging the skin between the pores. Gently squeeze the pimple to extract the infection. If in doubt about the pimples readiness for extraction, then keep applying a dot of lotion to it until it is ready. This may take a few days. Just be careful whatever you do and dont force it.
10. Always research new acne treatments. There are solutions today that did not exist when I was young, such as blue/red light therapy, growth factor and peptide serums, microneedling, newer medicinals, and laser treatments of many sort. Knowledge is power. Prevention is a must.