Which is better for covering up acne scars and acne, liquid or stick concealer? Are there any drugstore brands you would recommend? What's the difference between liquid concealer and liquid foundation?

#1 stick concealer is much more thicker so they will cover more.
#2 hey the difference between drug store brand and a good M.A.C brand will only be about $5-$10 so why don't u wait another month and save it for a good quality which lasts longer too. instead of throwing money away on cheap make up
#3 a concealer is much more concentrate than foundation so use concealer to hide scars and foundation to smooth skin complexion.

hope it helps ... good luck )

to hide acne scars i very much recommend 'Make Up Forever' Extreme Full Coverage Waterproof Concealer. Liquid concealer will not cover up the acne scars trust me. A waterproof concealer with extreme coverage will. You can find this product at Sephora.

Both do the same job so it's really about what's more convenient for you.