How can i make a picture like this?

[rich2005]

(08-06-2017, 02:02 PM)Rollie Wrote: .... Here is the sort of images i produce.

You are limiting yourself if working on that size image, if possible use larger images and as a final step, scale down to that thumbnail size.

Gmic again, the 'illustration filter followed by one from the lights & shadows section. Plenty to try, experiment and ctrl-z (undo) is your friend.