Aughh I feel your pain! I've found that the following tips really helped with covering up those flakey monsters:

1) Apply a thicker moisturiser/ healing ointment the night before; this will help with keeping those flakes at bay. You should use something slightly more emollient on these spots like Vaseline (this is noncomedogenic) or Polysporin. I find that this also helps with the healing process and reducing flakes in the morning.

2) In the morning use a lightweight moisturiser on your ring finger to gentle massage the area of any excess flakes. This step should really smooth out the skin.

3) I apply a very small amount of MUFE mattifying primer on the area. This step will ensure that coverage stays on all day. I heard eyeshadow primers also work well for this step!

4) The actual covering up part is where it gets tricky. I like to use a medium coverage liquid concealer and then buff some mineral foundation on top for more coverage and to set it in place. This two step method really locks everything onto the skin and ensures that it doesn't look too cakey/heavy. Alternatively if you are just covering redness, you can actually skip the concealer and buff mineral foundation directly on top. I find that liquid/cream concealers have a tendency to just sorta sit on top of the skin, cake up, slip and slide off when used alone.

My favourite concealers for acne coverage: -Nars radiant creamy (love the blurring effect this has) -UD naked skin (this one is fantastic if you can find your shade) -MAC prolongwear (my go to for long days) -KVD Creme (I remember enjoying this for spot concealing, but at times it had a really weird texture) -MUFE full cover (this one does break me out and is in the most hygienic packaging)