I'm going to share some of my techniques in digital illustration based on my own noob experience.
There are several types of illustration that I do :
- Digital illustration using hand-drawn stroke - on Photoshop
- Digital illustration using vector - on Illustrator
- Digital Illustration or Painting - on Photoshop
My favorite style is by using Photoshop because it will be more flexible to draw on my Wacom tablet almost naturally. The bad side for this technique : It will be a solid illustration, any changes mean you need to wipe it clean and draw it back. The size for the illustration will also be fixed, so you can't really enlarge it from the original size you started.
Compared to vector : the illustration will be super flexible, you can edit all the points or enlarge it as big as you want but, the styling will be a bit too clean for my liking.
To start, you need to know what you want to draw ie : the rough idea. A sketch on paper is good *you can scan it or snap a picture of it and open it on Photoshop, a rough moodboard from images taken from the net is also good - in this case, you can make a layout of what you want to draw and put all the items on the artboard and experiment with the size and location.
The size :
For any digital illustration that will only be used online : blog, ig, fb, etc -
Artboard : 1000 x 1000 pixel
Resolution : 150
Colour mode : RGB
For any printing artwork : poster, brochures, etc -
Artboard : Based on the printing size, it is advisable to use the size of your printing size as a reference. So you will make sure that the size of your illustration will be big enough to be printed later.
Resolution : 300 *the highest
Colour mode : CMYK *test print is your friend. iMac's screen usually show brighter and more colourful screen but your printed items might not.
I can't find my pencilled-sketch for this illustration. But yes, I did doodled this on a paper and snap a photo of it using my phone. Then I open a new psd file and paste it on one of the layer. I drew on the upper layer afterwards.
Here are the items on the illustration, on different layers because I like to rearrange it over and over again until I got something that I like :
Here is an illustration all arranged and ready to be coloured :
And here is the coloured version :
See? Illustrations that aren't vectorized always looked a bit personalized. It's my personal favorite style, I really like clean hand-drawn digital illustration like comic.
Most of my formal works use vectorized illustration because they are easier to amend - *clients are hard to please :F but most of my informal fun projects are in digital hand-drawn illustration. Down below is an example of the vectorized illustration from the same theme above *in lazy version, nothing that makes it look like my work, kan? :
So it depends on you, you can always try few other methods and see which style you like the most. As a visual designer, it is surely useful to know several different methods because you need to illustrate based on your client's need. Designers need to know how to manipulate visual items.
But for an illustrator, you need to have your own 'touch' that make your digital illustration came from you only. It's a live-long journey, the more you practice and experiment, the more style you'll come across and you will find something that you like the best that represents you.