I’m running Treaty of the Tiger King, by the Arcane Library, for my 5e beginners table. I am using the maps provided with the adventure to inspire my maps. I use vinyl map mats and washable markers.
Videos of map drawing will be coming soon. For now I have these process pictures to share.
This is the first stage of my maps. I just get down some general shapes in a light color.

Next I add some color to each block. In this case the blocks are buildings.

Then I use a damp towel to smooth out the marker lines, add some variance and texture. I try to do a quick job and remind myself that small ‘errors’ can become detail and nice texture or variety. I added some greenery near the entrances and other areas along the alleyways.

Finally I go back around the blocks and shapes with a dark color, making them distinct.

I have one final picture to take of the complete map.