Different scars, different treatments.
For acne/blemish scars on face:
Most acne scarring is due to post-inflammatory hyperpigmentation, which basically means after an inflammatory event like a pimple or rashes sometimes we develop darker scars due to over-production of melanin in that area. This is especially common in our asian skin!

The best way to treat that sort of scar is to use exfoliatives and lightening products. Exfoliating products help the skin to "shed" that upper layer faster so that the new skin underneath get to the surface faster. Lightening products may help in that they usually contain SPF which prevents extra darkening from the sun.
-Fix:
Exfoliators There are physical (scrubs, microdermabrasion) and chemical exfoliators. I advice against using physical exfoliators as they can further irritate the skin and cause more darkening, especially if used too often and too harshly. Chemical exfoliators like Salycilic and glycolic acid can be found in many toners out there. I suggest going to a dermatologist to find the best exfoliator for your skin type especially if dealing with severe cases. Use toners once a day at nighttime or every other day if you have really sensitive skin.
Sunscreen! (Broad spectrum UVA/UVB of atleast SPF30)
-Quick fix: Concealer can help mask the discoloration while waiting for the scarring to fade.
For Keloid/Hypertrophic scars:
I have quite a few of these on my legs too from an over-active childhood hehe. These types of scarring are harder to treat and depends on a LOT of different factors. Many people are also "keloid-formers" genetically predisposed to it. If you know you are one, the best treatment is prevention. If you go for any procedures or have a new scar you can tell your doctor that and have the right meds given to you to prevent them from forming.
Medications like Contractubex work in this fashion. However if we are dealing with an "old" scar (more than 2weeks to a month) those meds won't be that helpful as the scar tissue has already formed and medical therapies either take only little effect or require a very long time to show improvement.
-Fix:
Laser therapy and Cryotherapy (freezing) Kills off the scar tissue to reveal again healthier skin tissue underneath. Depending on your keloid size and age it may require several sessions. During sessions dermatologists usually give you medications to prevent new keloid formation.
Excision means surgical removal of the keloid. The doctor usually removes the entire keloid and sutures the skin so only a thin line remains. They then usually inject corticosteroids in the new scar so it won't form another keloid as well as topical medications like contractubex or dermatix.
-Quick fix: I love using Sally Hansens airbrush legs to cover up most of my scars. Best thing is that once it sets its waterproof so you can even go swimming with it.

Most important is to know that those scars don't define you and to be confident in your own skin. When I had just started dating my BF I was always nervous about my scars and opted to wear nothing but pants during our first few dates. One day I fell and skinned my knee through my leggings and he pushes my legging up to see my knee. I'm like shocked and horrified and thinking "oh no my scars" but he just cleans up my wounded knee. Later when I asked him what he thought of my scars he just says he didn't even notice them. He pulls up my leggings again and winks at me telling me I have great legs and should show them off more often.

I think with confidence you can pull anything off.
Cheers!