I like this sort of project because there is a rhythm to adding the next illustration all the time. I did them over a recent week after my father suddenly died. It was therapeutic as much as anything. He loved his garden.
I also like working with a soluble ink pen. I have two Rotring ArtPens in Fine and Extra Fine. They work a treat for sketching in the image and then wetting it judiciously to make the tones. I often use a Derwent water brush for this part, because a real paintbrush can often hold and release too much water.
The problem of next adding colour is that, although the ink dries pretty permanently where you’ve wetted it, the lines you deliberately left untouched will mix with any added wet colour. Most dry colour will cover lines up. I didn’t fancy coloured pencil – it would have felt like the recent ‘fill the holes’ colouring book craze!
For this reason, I usually take the scans into Photoshop or Clip Studio Paint (Manga Studio as was) or – as here – Procreate, one of the best drawing/painting apps on the iPad. As I have an iPad Pro, I can use my Apple Pencil, which is just wonderful for digital work. By setting the top, coloured layer to Multiply, the soluble ink shading stays visible and integrates.
Had this been for a commission, I would have made all the backgrounds exactly the same colour. The joy of a personal project is I can please myself!