I still use a grid system at times, although the squares are larger than normally used. I like using acrylics because I can work fast and easy to clean up LOL. The very first comic piece I ever did for a comic con in 2016.
I use Photoshop a lot to help place images together and alter images to get the desired effects I want. I like drawing/painting from an actual picture or at least to get the general lighting source correctly. I learned this from a book showing how the Hildebrandt Brothers created their art.
I created this for a client who wanted a replica of the artist "Retna" ... I used the bricks as a grid system to help line everything up. Took 2 days to do in 110 degree heat...but at least it was a "dry" heat