Hieroglyphics inscriptions consist of rows of individual hieroglyphs which can be arranged either in vertical lines (like in western writing) or in vertical columns (like Chinese writing).
Hieroglyphic writing usually reads from right to left however they can sometimes read left to right. Above all the Egyptians valued artistic balance and symmetry wherever possible – this was often the reason for a left to right reading order to be used for a panel.
Incidentally, modern texts dealing with hieroglyphics tend to work left to right to conform with modern writing preferences (WE do this on this site too – that’s why all of our symbols face left!)
Despite the various ways in which hieroglyphs can be written it is quite easy to see where to start – the beginning of the inscription is indicated by the direction that the characters (people, birds, snakes etc.) are facing.
In this sentence, you would read left to right, since all the animals face left.
However, in this situation you would read right to left – since the birds face right.
Hieroglyphs in an upper position have a preference over those in a lower position.